ASSET PURCHASE AGREEMENT

     This Asset Purchase  Agreement (this  "Agreement")  dated as of December 1,
2003, is among NICHOLS  LABORATORIES,  INC., an Illinois Corporation  ("Buyer");
and UNITED  STATES DRUG  TESTING  LABORATORIES,  INC.,  an Illinois  corporation
("Seller") and Avitar, Inc., a Delaware corporation ("Avitar").

                                    RECITALS

     Seller  desires  to sell,  and  Buyer  desires  to  purchase,  the  certain
specified  assets of Seller  necessary  and used in  Seller's  drug  testing and
research  business  (the  "Business")  now owned  and  operated  by Seller  (the
"Assets", but excluding certain Assets specified in Section 1.02), and Buyer has
agreed to assume all  liabilities  of the Seller  arising from or related to the
Business (the  "Liabilities",  but excluding  certain  Liabilities  specified in
Section  1.04  and  1.04A),  on the  terms  and  conditions  set  forth  in this
Agreement.  As an integral part of the  foregoing  transaction,  Avitar,  as the
owner of all of the outstanding  shares of the Seller, and the Buyer have agreed
to enter into a Service and  Consulting  Agreement  by which Buyer will  provide
certain laboratory,  analytical, testing and consulting services to Avitar for a
period of three years,  renewable for additional one-year terms absent notice by
either party as provided  therein.  It is mutually agreed that it is in the best
interests of the parties to this Agreement for all these transactions to occur.

     In  consideration  of the above  premises  and of the mutual  promises  and
covenants  contained  in  this  Agreement,  and  for  other  good  and  valuable
consideration,  the receipt and sufficiency of which is hereby acknowledged, the
parties agree as follows:



                                    ARTICLE 1
                           Purchase and Sale of Assets

     1.01  Purchase and Sale.  Subject to all the terms and  conditions  of this
Agreement and for the  consideration  herein stated, on the Closing Date, Seller
agrees to sell, convey, assign,  transfer and deliver to Buyer, and Buyer agrees
to purchase and accept from  Seller,  all of the Assets (but  excluding  certain
Assets   specified  in  Section  1.02),   which  Assets  shall  include  without
limitation:

          1.01-2 To the  extent  transferable,  the items of  tangible  personal
     property of Seller, including furniture,  fixtures,  equipment,  materials,
     supplies,  motor  vehicles,  inventory  and  spare  and  replacement  items
     therefor, listed on Schedule 1.01-2 ("Tangible Personal Property");

          1.01-3 To the  extent  transferable,  the  leases of real or  personal
     property listed on Schedule 1.01-3 (collectively, the "Leases");

          1.01-4 To the extent transferable,  all rights, benefits and interests
     of Seller under the  contracts,  agreements,  commitments,  understandings,
     purchase  orders,  sales  orders,  distributor  contracts,   manufacturer's
     representative  contracts,  documents  and  instruments  listed on Schedule
     1.01-4   hereto   and  under  any   contracts,   agreements,   commitments,
     understandings,  purchase orders,  and sales orders arising from or related
     to the  Business,  all of which  shall  be  expressly  assumed  by Buyer in
     writing on the Closing Date (collectively, the "Contracts");

          1.01-5 To the extent  transferable,  the  patents,  trademarks,  trade
     names,  copyrights and service marks of Seller, all registrations therefor,
     all  applications  pending  therefor and all other  proprietary  rights and
     intangible property of Seller, listed on Schedule 1.01-5;

          1.01-6 To the  extent  transferable,  the  approvals,  authorizations,
     consents,  licenses,  permits,   franchises,   tariffs,  orders  and  other
     registrations  of any federal,  state or local court or other  governmental
     department,   commission,   board,   bureau,   agency  or  instrumentality,
     (collectively the "Permits") held by Seller and required for the conduct of
     the Business, as listed on Schedule 1.01-6.

          1.01-7 The specified accounts receivable listed on Schedule 1.01-7.

          1.01-8 The specified  prepaid and deferred items of Seller,  including
     prepaid rent,  insurance,  taxes and unbilled charges and deposits relating
     to the Business, listed on Schedule 1-01-8;

          1.01-9  Copies  of all  operating  data and  records  relating  to the
     Business,  including without  limitation  financial,  accounting and credit
     records,  correspondence,  budgets,  engineering and laboratory records and
     other similar documents and records;

          1.01-10 All of Seller's  right,  title and interest in and to Seller's
     name "United States Drug Testing  Laboratories"  and "Mecstat" and "Mecstat
     Laboratories";

          1.01-11 All of Seller's  right,  title and interest in and to Seller's
     telephone, facsimile and telex numbers;

          1.01-12 All of Seller's  right,  title and interest in and to Seller's
     WebSite address,  the Seller's WebSite and Seller's entire right, title and
     interest in and to all current and archived content, including all web site
     pages,  currently  used or  previously  developed  in  connection  with the
     Business,  all media on which such  content is stored and any  inventory of
     written  materials,   whether  in  printed  form  or  on  film,  microfilm,
     microfiche or other negative,  and all lists of subscribers,  customers and
     content contributors.

     1.02 Excluded Assets. The Assets shall not include the following:

          1.02-1 Seller's  corporate seal,  minute books,  charter documents and
     corporate stock record books;

          1.02-2 Seller's cash and bank accounts.

          1.02-3 The assets identified on Schedule 1.02-3, if any.

     1.03 Purchase Price;  Payment of Purchase Price;  Sublease  Agreement.  The
aggregate  purchase  price for the Assets (the  "Purchase  Price")  shall be One
Million Dollars ($1,000,000.00), payable as follows:

          1.03-1. The Buyer shall make a down payment to the Seller or its order
     in the amount of Five Hundred Thousand  Dollars  ($500,000) in cash payable
     in two equal installments of Two Hundred Fifty Thousand Dollars ($250,000),
     with the first payment  payable on the Closing Date and the second  payment
     payable on a date up to sixty days after the  Closing  Date,  but not later
     than December 31, 2003.

          1.03-2.  The balance of the purchase  price of Five  Hundred  Thousand
     Dollars ($500,000.00) shall be payable to the Seller or its order beginning
     on March 1, 2005, on the following terms and conditions:

          (a) Buyer shall pay to the Seller or its order annual payments, due on
          March 1, 2005, and on the first day of March for each  successive year
          until the balance of the  purchase  price is paid,  an amount equal to
          ten percent  (10%) of the Buyer's  Annual Gross Sales  (subject to the
          adjustments  as set forth below) in excess of One Million Five Hundred
          Thousand Dollars  ($1,500,000.00) for the immediately preceding twelve
          month fiscal year ending on December  31st of each year.  For purposes
          of this Agreement,  the foregoing  annual payment shall be referred to
          as the "Annual Percentage Payment".  Buyer's obligations to Seller and
          to Avitar shall cease when the aggregate  Annual  Percentage  Payments
          made to Seller  and to Avitar  reach  Five  Hundred  Thousand  Dollars
          ($500,000.00).

          (b) For purposes of this Agreement, the Buyer's "Gross Sales" for each
          Fiscal Year shall  include the gross income to the Buyer from the sale
          of drug testing materials,  analytical services, drug testing services
          and drug testing kits, less returns and allowances.  Gross Sales shall
          also include income from  subcontracts for research  services provided
          to any third parties.  Gross Sales shall not include: (i) the value or
          amount of any  sales by Buyer to Avitar  which  sales are  subject  to
          offset or credit  under  this  Agreement;  (ii) any  direct  income or
          direct  grant  award to the Buyer from the Small  Business  Innovative
          Research  Program  (SBIR) or income  or  direct  grant  from the Small
          Business Technology Transfer Program (STTR) Phase I, Phase II or Phase
          III (the "Grant Income");  (iii) consulting or expert witness fees for
          forensic  toxicology  matters;  (iv) income from leases or sub-leases;
          (iv)  royalty  income;  or (v)  ordinary  or capital  gain income from
          investments.  Notwithstanding the foregoing, the Grant Income shall be
          included  in and  added  to Gross  Sales  (i) to the  extent  that the
          aggregate  amount of the Grant  Income  exceeds one third (1/3) of the
          Buyer's Gross Sales for any three  consecutive  calendar  years during
          the term of this Agreement, and (ii) provided that there is no Federal
          or State law or  regulation  that would  prohibit  the  sharing of the
          Grant Income with the Seller and Avitar.

          (c) The  Annual  Percentage  Payment  will be reduced  annually  by an
          amount  equal to the combined  sums due  annually  from the Seller and
          Avitar to the Buyer for the services and products  ordered and used by
          the Seller and Avitar  under the terms of the Service  and  Consulting
          Agreement,  attached  hereto as Exhibit A, pursuant to which the Buyer
          shall provide  consulting and testing services to Seller and to Avitar
          following the Closing.

          (d) Buyer  agrees that in the event that the Buyer sells or  transfers
          all or a substantial portion of the Assets and the business operations
          of the  Business to a third party while any part of the balance of the
          purchase  price remains  unpaid,  that in such event the entire unpaid
          balance then payable to Seller and Avitar shall be paid in full at the
          time of the sale or transfer.  For purposes of this section,  a "third
          party"  refers to any person or separate  business  entity that is not
          owned or controlled by the Buyer.

          (e) Avitar and Seller shall have the right to conduct an annual review
          or audit of Buyer's  Gross Sales,  which Gross Sales shall be reported
          annually to Avitar and Seller by Buyer within 90 days after the end of
          each year. Buyer shall, upon reasonable terms and at reasonable times,
          provide  access to such tax returns and financial  records of Buyer as
          may be necessary for the sole purpose to allow Avitar and/or Seller to
          review  or audit  the  Buyer's  Gross  Sales.  Any such  access to tax
          returns  and  financial  records  shall be granted  with due regard by
          Avitar  and  Seller to the  protection  of  Buyer's  confidential  and
          private financial  information and any requirement of  confidentiality
          of medical  records or  information  as  required by law. If the Gross
          Sales as  reported by Buyer in any year are more than 5% less than the
          actual Gross Sales for such year as determined by Avitar and/or Seller
          after review or audit,  then (i) Buyer shall be obligated to reimburse
          for all costs incurred in the review or audit and (ii) the Buyer shall
          be  obligated  to increase  the annual  payments due to the Seller and
          Avitar on the balance of the remaining  purchase in an amount equal to
          20% of the  discrepancy  between the Gross Sales as  determined by the
          audit and the Gross Sales as previously reported by Buyer.

          1.03-3  From the  Closing  Date until such times as the balance of the
     down  payment is fully paid by Buyer,  the Buyer  agrees to deposit  all of
     Buyer's  shares under a stock pledge  escrow  agreement to Avitar to secure
     the balance of the down payment. The stock pledge escrow agreement shall be
     in the form set forth in Exhibit  A-1.  Upon  payment of the balance of the
     down  payment,  the escrow under the stock pledge  escrow  agreement  shall
     release all shares to Buyer. In addition, until such time as the balance of
     the down payment is made by Buyer,  Buyer agrees not to encumber its assets
     in excess of One Hundred Fifty Thousand Dollars ($150,000).

     1.04 Assumption of Liabilities.  Subject to the exceptions  provided in the
following  Section  1.04A,  as of the Closing  Date,  the Buyer shall assume and
agree to  perform  and pay  when due all  debts,  liabilities,  obligations  and
contracts of Seller of every kind,  character or description,  known or unknown,
existing  at the time of the  Closing  Date,  including  contingent  liabilities
("Assumed Liabilities").

     1.04A Certain Liabilities Not Assumed.  Notwithstanding the foregoing,  the
assumption by Buyer of the  foregoing  debts,  liabilities  and  obligations  of
Seller shall expressly exclude the following:  (a) the inter-company  receivable
as of the Closing  Date  between  Avitar and Seller  (solely for  identification
purposes  the  inter-company  receivable  as of  9/30/03  as  reflected  in  the
September  30,  2003  Balance  Sheet  attached  hereto  was  $881,000);  (b) all
liability  of any kind,  including  any  transferee  liability,  for all  taxes,
assessments,  penalties, interest and fines in connection with any tax including
but not limited to  unemployment  tax,  social  security tax,  withholding  tax,
medicare tax, sales tax, use tax, income tax, corporate  replacement tax, estate
tax,  inheritance  tax, or gift tax, due to any government or unit of government
related to or arising  out of the  operations  or conduct of  business by Avitar
(but  expressly  excluding  from this Section 1.04A any operations or conduct of
business of  Seller);  (c) all  liability  for any lawsuit or legal claim of any
kind, whether or not covered by insurance,  including claims for malpractice and
product  liability,  relating to or arising out of the conduct or  operations of
Avitar's  business  (but  expressly   excluding  from  this  Section  1.04A  any
operations  or conduct of business of Seller);  and (d) liability for all debts,
security  interests,  claims and  assessments not appearing on the September 30,
2003 Balance  Sheet and arising out of the  operations or conduct of business by
Avitar (but  expressly  excluding  from this  Section  1.04A any  operations  or
conduct of business of Seller).

     1.05  LINC  Credit  LLC and  Republic  Finance  Indebtedness  and  Security
Interest; Buyer's Right of Set-Off.

          1.05-1 Seller  represents to Buyer that: (a) there is an  indebtedness
     on a note and  security  agreement  due to LINC Credit LLC in the amount of
     less than $61,000.00 (the "LINC  Indebtedness");  (b) the final payment due
     on the LINC  Indebtedness  is due prior to December  5, 2003;  (c) the LINC
     Indebtedness is now owned and held by Republic Finance;  and (d) the Assets
     to be sold to the Buyer are encumbered by the security interest in favor of
     LINC Credit LLC. True and correct  copies of the three loan  documents that
     evidence  the LINC  Indebtedness  are  listed in  Schedule  1.05 and copies
     thereof have been delivered to Buyer.

          1.05-2 Seller and Avitar agree to make timely payments due on the LINC
     Indebtedness  and use commercially  reasonable  efforts to obtain a release
     and satisfaction of the LINC Indebtedness promptly after payment when due.

          1.05-3 In the event that the LINC Indebtedness cannot be satisfied and
     released on or before the Closing  Date,  and as an inducement to the Buyer
     to Close  notwithstanding the foregoing unpaid obligation of the Seller and
     Avitar, Seller and Avitar agree as follows:

          (a) Seller and Avitar  agree to make timely  payments  due on the LINC
          Indebtedness  after the  Closing  Date.  Seller  and  Avitar  agree to
          promptly  provide Buyer with evidence of timely payment of all amounts
          due under the LINC Indebtedness after the Closing Date; on the Closing
          Date, Seller and Avitar shall provide Buyer with satisfactory evidence
          of the balance  due under the LINC  Indebtedness  and shall  deliver a
          written statement at Closing authorizing the delivery of copies of all
          canceled  loan  documents  and a  termination  statement or release to
          Buyer.

          (b) Notwithstanding any other provision of this Agreement,  Seller and
          Avitar  agree  to pay the  LINC  Indebtedness  in  full  on or  before
          December  5, 2003 and to obtain a full  release and  satisfaction  and
          termination  statements  and  promptly  forward  the same  directly to
          Buyer.

          (c) Seller and Avitar agree to  indemnify,  protect and hold  harmless
          Buyer  from  and  against  any  loss,  claim,  or  expense  (including
          reasonable  attorneys  fees and court  costs)  incurred or expended by
          Buyer as a result of Seller or Avitar's non-payment or late payment of
          the LINC Indebtedness.

          (d) Seller and Avitar  agree that in the event of any  non-performance
          or breach of the  foregoing  provisions of this  subsection  1.05-3 by
          Seller or Avitar, or if Buyer becomes entitled to seek indemnification
          under the  preceding  indemnification  provision,  then Buyer shall be
          entitled to a full right of set-off  against  any  amounts  that would
          otherwise  be  subsequently  due to the Seller  and/or to Avitar under
          this Agreement.

     1.06  Instruments  of  Conveyance  and  Transfer.   The  sale,  conveyance,
assignment,  transfer  and  delivery of the Assets shall be effected by Seller's
execution  and  delivery  to Buyer,  on the Closing  Date,  of a bill of sale in
substantially  the form of the  Assignment  and Bill of Sale attached  hereto as
Exhibit  B,  together  with such  other  assignments  and other  instruments  of
transfer and conveyance,  in form and substance  sufficient to vest in Buyer all
right, title and interest in and to the Assets, as reasonably requested by Buyer
or its counsel.

     1.07 Further Assurances. Seller and Avitar agree that, at any time and from
time to time on and after the Closing Date,  it will,  upon the request of Buyer
and without further consideration,  take all steps reasonably necessary to place
Buyer in possession and operating  control of the Assets,  and Seller and Avitar
will do, execute,  acknowledge and deliver, or will cause to be done,  executed,
acknowledged  and  delivered,   all  further  acts,  assignments,   conveyances,
transfers,  powers of attorney or  assurances  as  reasonably  required to sell,
assign,  convey,  transfer,  grant,  assure and confirm to Buyer,  or to aid and
assist in the  collection  of or reducing to  possession by Buyer of, all of the
Assets, or to transfer to Buyer the entire right, title and interest now held by
Seller in and to the Assets.  [Buyer gets what  Seller  has;  no  obligation  of
Seller/Avitar  to improve  whatever Seller has now.  Seller/Avitar is willing to
give the representation as to good title in Section 3.07 because it is qualified
by Buyer's representations in Section 2.05 and Section 5.05. ]

     1.08 Closing.  The  consummation of the  transactions  contemplated by this
Agreement (the "Closing") shall take place at the offices of Buyer's  attorneys,
at 70 West Madison Street, Suite 1400, in Chicago, Illinois on December __, 2003
(the "Closing Date") on or before the hour of 11:00 a.m.

     1.09 Deliveries at Closing.

          1.09-1 At the Closing, the Buyer shall deliver the following: (a) Cash
     down payment of Two Hundred Fifty Thousand  Dollars  ($250,000.00)  by wire
     transfer to Seller's account or Seller's legal  representative's  escrow or
     special account pursuant to the Seller's  written  direction at or prior to
     the Closing.  (b) The Services and Consulting  Agreement between Avitar and
     Buyer in the form of Exhibit  A. (c)  Assumption  Agreement  in the form of
     Exhibit C. (d)  Corporate  resolutions  and  certificates  authorizing  the
     execution  and  performance  of the  Agreement.  (e)  Stock  Pledge  Escrow
     Agreement in the form of Exhibit A-1. (f) Mutual General  Releases  (except
     for  obligations  under this  Agreement)  by Avitar and Seller,  on the one
     side, and Buyer and Buyer's  principals,  Douglas Lewis and Veronica Lewis,
     on the other side; in the form of Exhibit A-2(i) and Exhibit  A-2(ii).  (g)
     Such other  fully  executed  documents  or  instruments  of  conveyance  or
     transfer  as  are  contemplated  by  Section  1.06,  or  as  are  otherwise
     reasonably  contemplated  by the terms and  provisions  of this  Agreement,
     including without  limitation a resignation letter from Douglas Lewis as an
     employee of Seller and as an officer of Avitar.

          1.09-2 At the Closing,  the Seller and Avitar shall  deliver to Buyer:
     the  executed  Assignment  and Bill of Sale in the form of  Exhibit  B; (b)
     subject to the  provisions  of Section  1.05,  full  releases,  termination
     statements  and proof of payment for any and all security  interests in the
     assets to be sold and  transferred to the Buyer;  (c) articles of amendment
     to the articles of  incorporation  of Seller  changing the Seller's name of
     "United States Drug Testing Laboratories, Inc." to some other unrelated and
     dissimilar name; trademark or trade name and patent assignments in the form
     of Exhibit B-2; and Corporate resolutions and certificates  authorizing the
     execution and performance of the Agreement; and (f) such other documents or
     instruments  of  conveyance  or transfer as  contemplated  by Section 1.06,
     above,  and as  contemplated  by the  other  terms and  provisions  of this
     Agreement.

          1.09-3 At the  Closing,  Avitar  shall  deliver:  (a) the Services and
     Consulting Agreement between Avitar and Buyer in the form of Exhibit A; and
     (b) such other fully executed  documents or instruments and counterparts of
     documents or instruments as  contemplated by the other terms and provisions
     of this Agreement.

ARTICLE 2 Representations and Warranties of Buyer

     Buyer represents and warrants to Seller and Avitar as follows:

     2.01  Authorization.  Buyer  is  a  corporation,  duly  organized,  validly
existing  and in good  standing  under the laws of the State of Illinois has all
requisite corporate power and authority to own and operate its properties and to
carry on its business as now  conducted.  Buyer has taken all  corporate  action
necessary  to  authorize  its  execution,   delivery  and  performance  of  this
Agreement.  Buyer has full  corporate  power and  authority  to enter  into this
Agreement and carry out the terms hereof.  Buyer has duly executed and delivered
this Agreement and the other  agreements and  undertakings  contemplated by this
Agreement.  This  Agreement is its valid and binding  obligation  enforceable in
accordance with its terms, except as enforceability may be limited by or subject
to any bankruptcy, insolvency, reorganization, moratorium or other similar laws,
now or hereafter in effect,  relating to creditors'  rights  generally or by the
availability of equitable remedies.

     2.02 Compliance. The execution,  delivery and performance of this Agreement
by Buyer,  the compliance by Buyer with the provisions of this Agreement and the
consummation of the  transactions  described in this Agreement will not conflict
with or result in the breach of any of the terms or  provisions of or constitute
a default under:

          2.02-1 the articles of incorporation or bylaws of Buyer;

          2.02-2 any note, indenture,  mortgage,  deed of trust, loan agreement,
     lease or other  agreement  or  instrument  to which  Buyer is a party or by
     which Buyer is bound; or

          2.02-3 any statute or any order,  rule,  regulation or decision of any
     court or regulatory authority or governmental body applicable to Buyer.

     2.03 Consents. Except as set forth in Schedule 2.03, no consent,  approval,
authorization,  order,  designation  or  declaration  of any court or regulatory
authority or governmental body, federal or other, or third person is required to
be  obtained  by Buyer nor is any  filing or  registration  required  to be made
therewith by Buyer for the  consummation of the  transactions  described in this
Agreement.

     2.04  Brokers  and  Finders.  Neither  Buyer nor any  officer,  director or
employee  of Buyer has  employed  any  broker,  finder or  investment  banker or
incurred any liability for any commission,  brokerage or investment  banking fee
or  finder's  fee in  connection  with  the  transactions  contemplated  by this
Agreement.

     2.05  Representations  and Warranties of Buyer In Regard To Seller.  To the
best knowledge of Buyer and its officers and shareholders,  the  representations
and  warranties  of Seller and the  schedules  attached  to this  Agreement  are
accurate and complete in all material respects.


                                    ARTICLE 3

     Representations and Warranties of Seller and Avitar

     3.01 Corporate Existence.  Seller is a corporation duly organized,  validly
existing and in good standing under the laws of the State of Illinois and Seller
has all necessary  corporate  power and authority to own,  lease and operate its
properties  and  assets and to carry on its  business  as now  conducted  and as
proposed to be conducted. Seller is duly qualified or licensed to do business as
a foreign  corporation  and in good standing in each  jurisdiction  in which the
property  owned,  leased or  operated  by it or the  nature of its  business  or
activities  or ability to perform the  transaction  completed by this  agreement
makes such qualification or licensing necessary.

     3.02  Authority.  Seller and Avitar have full corporate power and authority
to enter into this Agreement and all other agreements, documents and instruments
executed  and  delivered  in  connection  herewith and to carry out their terms.
Seller and Avitar have taken all  corporate  action  necessary to authorize  the
execution,  delivery and performance of this Agreement.  This Agreement has been
duly and validly  executed  and  delivered  by Seller,  and is binding  upon and
enforceable  against Seller and Avitar in accordance  with its terms,  except as
enforceability may be limited or affected by applicable bankruptcy,  insolvency,
reorganization or other laws of general application relating to or affecting the
rights of creditors and except as enforceability  may be limited by rules of law
governing specific  performance,  injunctive relief or other equitable remedies.
The Seller and Avitar are not now insolvent.

     3.03 No Adverse  Consequences.  Neither the  execution and delivery of this
Agreement  by  Seller  and  Avitar  nor  the  consummation  of the  transactions
contemplated by this Agreement will:

          3.03-1  result in the creation or  imposition  of any lien,  charge or
     encumbrance on any of Seller's assets or properties,

          3.03-2 violate or conflict with any provision of Seller's  articles of
     incorporation or bylaws,

          3.03-3 violate any law, judgment,  order,  injunction,  decree,  rule,
     regulation or ruling of any governmental  authority applicable to Seller or
     Avitar, or

          3.03-4  either  alone or with the  giving of notice or the  passage of
     time  or  both,  conflict  with,  constitute  grounds  for  termination  or
     acceleration  of,  result  in  the  breach  of  the  terms,  conditions  or
     provisions of, result in the loss of any benefit to Seller and Avitar under
     or constitute a default under any agreement,  instrument, license or permit
     to which either Seller and Avitar is a party.

     3.04 Brokers and  Finders.  Seller and Avitar have not employed any broker,
finder or agent or dealt  with  anyone  purporting  to act in such  capacity  or
agreed to pay any brokerage fee,  finder's fee or commission with respect to the
transaction contemplated by this Agreement.

     3.05  Litigation.  There is no material  claim,  litigation,  proceeding or
investigation  of any kind pending or threatened by or against Seller and Avitar
and, to the best knowledge of Seller and Avitar,  there is no basis for any such
claim, litigation, proceeding or investigation.

     3.06 Title to Assets.  Seller has good and absolute  title to the Assets to
be sold to Buyer.  At the Closing,  the Buyer will acquire good title to all the
Assets, free and clear of all mortgages,  pledges,  security interests,  claims,
charges  or other  encumbrances  or  restrictions  of any kind,  except  for the
encumbrances related to Assumed Liabilities and except for the LINC Indebtedness
referred to in Section 1.05, above.

     3.07 Taxes.

          3.08-1  Returns.  Seller has timely filed all federal,  state,  local,
     foreign and other returns, reports, information returns and declarations of
     estimated  tax  required  to  be  filed  by  Seller,   including,   without
     limitation, returns or reports with respect to backup withholding and other
     payments to third parties  (collectively,  the  "Returns"),  and has timely
     paid all taxes  shown to be due on (or  required to have been shown on) the
     Returns or  otherwise  required to be paid with respect to any period prior
     to the date of this Agreement.  Seller has not received any notice of audit
     and there are no outstanding agreements or waivers extending the applicable
     statutory periods of limitation for such taxes for any period.  All Returns
     filed are complete and accurate in all material  respects and no additional
     taxes are owed by Seller.

     3.08 Effect of Transfer.  Neither Seller nor Avitar are currently insolvent
or unable to pay their debts,  liabilities  and  obligations as they become due,
and the  transfer  of the  Assets  to Buyer  will not  render  Seller  or Avitar
insolvent  or unable to pay their debts,  liabilities  and  obligations  as they
become due.

     3.09 No Interest in Other  Entities.  No shares of any  corporation  or any
ownership or other investment  interest or business interest,  either of record,
beneficially or equitably,  in any  association,  partnership,  joint venture or
other legal entity are included in the Assets.

     3.10 Absence of  Undisclosed  Liabilities.  To the best of the knowledge of
Seller and Avitar,  the Seller has no liabilities or obligations with respect to
the  Business,  either  direct or  indirect,  matured or  unmatured or absolute,
contingent or otherwise,  except for those liabilities or obligations of Seller:
(a)  that  are  set  forth  on the  Balance  Sheet  and not  heretofore  paid or
discharged;  (b) that have arisen in the ordinary  course of  business;  and (c)
that have been  incurred  consistently  with past  business  practice in or as a
result of the normal and ordinary  course of the Business.  For purposes of this
Agreement, the term "liabilities" shall include, without limitation,  any direct
or  indirect   indebtedness,   guaranty,   endorsement,   claim,  loss,  damage,
deficiency, cost, expense, obligation or responsibility, fixed or unfixed, known
or  unknown,  asserted  or  unasserted,   choate  or  inchoate,   liquidated  or
unliquidated, secured or unsecured.

     3.11 Books of Account.  To the best of the  knowledge of Seller and Avitar,
the books,  records and accounts of the Seller as maintained and approved by the
officers and agents of Avitar with respect to the Business accurately and fairly
reflect,  in reasonable  detail, the transactions and the assets and liabilities
of the Seller  with  respect  to the  Business.  The Seller and Avitar  have not
engaged in any  transaction  with respect to the Business,  maintained  any bank
account  for the  Business or used any of the funds of the Seller in the conduct
of the Business except for transactions, bank accounts and funds which have been
and are reflected in the normally maintained books and records of the Business.

     3.12  Completeness  of  Disclosure.  No  representation  or warranty by the
Seller or Avitar in this  Agreement nor any  certificate,  schedule,  statement,
document or instrument furnished or to be furnished to Buyer pursuant hereto, or
in connection with the negotiation,  execution or performance of this Agreement,
contains or will  contain any untrue  statement  of a material  fact or omits or
will omit to state a material  fact  required to be stated  herein or therein or
necessary to make any statement herein or therein not misleading.

                                    ARTICLE 4

     Employees and Audit Support

     Buyer will offer,  and use its best efforts,  to employ effective as of the
Closing Date all current employees of Seller on substantially the same terms and
conditions as those upon which they were employed by Seller prior to the Closing
Date.  Buyer  will do  whatever  is  customary  or  appropriate,  or  reasonably
required,  to permit Avitar's auditors to complete the audit of the Business for
the fiscal year ended September 30, 2003.

                                   ARTICLE 4A

     Joint Covenants

     Buyer,  Seller  and  Avitar  covenant  and  agree  that they will use their
respective  best  efforts  to  effect  the  transactions  contemplated  by  this
Agreement,  to promptly execute or cause to be executed all related undertakings
and agreements required to be executed or contemplated by this Agreement, and to
fulfill  the  conditions  of this  Agreement.  No party  will  take  any  action
inconsistent  with its obligations  under this Agreement or that could hinder or
delay the consummation of the transactions contemplated by this Agreement.

                                    ARTICLE 5

     Survival; Indemnification

         5.01 Survival. All representations, warranties, covenants and
agreements made in this Agreement or in any exhibit, schedule, certificate or
agreement delivered in accordance with this Agreement shall survive any
investigation by or on behalf of any party, the execution and delivery of this
Agreement, the consummation of the transactions contemplated hereby and any
termination or expiration of this Agreement. The representations, warranties,
covenants and agreements made in this Agreement shall continue in full force and
effect until the later of (a) a period of five years following the Closing Date
or (b) the date that all obligations due to Avitar and Seller are paid in full
by Buyer.

     5.02 Indemnification by Seller and Avitar.

          5.02-1  Notwithstanding any investigation by Buyer, from and after the
     Closing,  Seller and Avitar, jointly and severally,  shall indemnify,  hold
     harmless and, defend Buyer,  its  subsidiaries,  shareholders,  affiliates,
     officers,   directors,    employees,   agents,   successors   and   assigns
     (collectively,   "Buyer's  Indemnified  Persons")  from  and  against,  and
     reimburse each of Buyer's  Indemnified Persons with respect to, any and all
     losses, damages,  liabilities,  costs and expenses, including interest from
     the date of such  loss to the time of  payment,  penalties  and  reasonable
     attorneys'  fees  (collectively,  "Damages")  incurred  by any  of  Buyer's
     Indemnified  Persons by reason of or arising out of or in  connection  with
     the  following,  whether  or not a claim  is made  against  any of  Buyer's
     Indemnified Persons by any third party:

          (a)  any  material  breach  or  inaccuracy  of any  representation  or
          warranty  of  Seller  or  Avitar  made in  this  Agreement  (it  being
          understood  and  agreed  that  any  liability  of any  kind,  known or
          unknown,  contingent or otherwise,  assumed by Buyer shall in no event
          be  deemed  to be a breach  or  inaccuracy  of any  representation  or
          warranty of Seller or Avitar);

          (b) any  material  failure by Seller or Avitar to perform any covenant
          required to be performed by it or them pursuant to this Agreement; or

          (c) any material liability or obligation of Seller or Avitar specified
          in Section 1.04A . In connection  with the foregoing  indemnification,
          the Buyer shall be entitled to enforce its right to indemnification by
          a full right of offset against the balance due to Seller and to Avitar
          under Section 1.03-2.

     5.03 Indemnification by Buyer.

          5.03-1 Notwithstanding any investigation by Seller or Avitar, from and
     after the Closing,  Buyer shall indemnify,  hold harmless and defend Seller
     and  Avitar,  their  respective  subsidiaries,   shareholders,  affiliates,
     officers,   directors,    employees,   agents,   successors   and   assigns
     (collectively,  "Seller's  and  Avitar's  Indemnified  Persons")  from  and
     against,  and reimburse each of Seller's and Avitar's  Indemnified  Persons
     with  respect  to, any and all  Damages  incurred  by any of  Seller's  and
     Avitar's  Indemnified  Persons  by  reason  of  or  arising  out  of  or in
     connection  with the following,  whether or not a claim is made against any
     of Seller's and Avitar's Indemnified Persons by any third party:

          (a) any breach or  inaccuracy  of any  representation  or  warranty of
          Buyer made in this Agreement;

          (b) any  failure  by Buyer to  perform  any  covenant  required  to be
          performed by it pursuant to this Agreement; or

          (c) any liability or obligation of Seller or Avitar to any third party
          expressly  assumed  by Buyer  in  accordance  with  the  terms of this
          Agreement.

     In  connection  with the foregoing  indemnification,  the Seller and Avitar
shall be  entitled to enforce  its right to  indemnification  by a full right of
offset  against any balance  that may be due to Buyer  under this  Agreement  or
otherwise.

     5.04 Rights Not Exclusive. An indemnified party's rights to indemnification
under this  article are in addition  to, and not in lieu of, any other rights to
which the indemnified party may be entitled at law or in equity.

     5.05  Buyer's  Special  Status and Waiver of Claims By Buyer.  All  parties
acknowledge  that Douglas Lewis and Veronica Lewis previously sold the shares of
Seller to Avitar and that Douglas  Lewis has served as President of Seller since
its  inception  and  that  Douglas  Lewis  will  be the  principal  manager  and
supervisor  of the Seller's  Business  after it is acquired by the Buyer.  Buyer
agrees not to assert any claim for damages or  indemnification  or maintain  any
action or suit based on a breach of warranty or  misrepresentation  by Seller or
Avitar if Douglas  Lewis or Veronica  Lewis had knowledge or reason to know that
such warranty or  representation  was untrue or inaccurate  when made. It is the
express  understanding  of the  parties  that Buyer  cannot  take  advantage  of
information  that was  known or  should  have  been  known by  Douglas  Lewis or
Veronica Lewis as of the date of this Agreement or the Closing Date.

                                    ARTICLE 6

     Confidentiality; Press Releases

     6.01 Confidentiality.

          6.01-1  No  information  concerning  Seller  or  Avitar  that has been
     furnished to or obtained by Buyer in connection  with this Agreement  shall
     be disclosed to any person other than in  confidence  to  employees,  legal
     counsel,  financial advisers or independent public accountants of Buyer who
     Buyer  reasonably  determines  have a need  to  know  such  information  in
     connection with this Agreement. If this Agreement is not consummated, Buyer
     shall hold such  information  in confidence  for a period of two years from
     the date of termination of this Agreement.

          6.01-2 No information concerning Buyer not previously disclosed to the
     public or in the public  domain that has been  furnished  to or obtained by
     Seller or Avitar in connection  with this  Agreement  shall be disclosed to
     any person  other  than in  confidence  to the  employees,  legal  counsel,
     financial advisers or independent public accountants of Seller or Avitar or
     used for any purpose other than as contemplated herein.

          6.01-3 Notwithstanding the foregoing, such obligations of Buyer and of
     Seller and Avitar shall not apply to information

          (a) that is, or becomes,  publicly  available from a source other than
          Buyer or Seller or Avitar;

          (b) that was known and can be shown to have been known by Buyer at the
          time of its receipt  from Seller or Avitar,  or by Seller or Avitar at
          the time of its receipt from Buyer;

          (c) that is  received by Buyer from a third  party  without  breach of
          this  Agreement  by Buyer,  or is  received by Seller or Avitar from a
          third party without breach of this Agreement by Seller or Avitar;  (d)
          that is required by law to be  disclosed;  or (e) that is disclosed in
          accordance with the written consent of Buyer or of Seller or Avitar.

     6.02  Press  Releases.  No press  releases  or other  public  announcements
concerning the  transactions  contemplated  by this  Agreement  shall be made by
either party without the prior written consent of the other party which consent,
in either case, shall not be unreasonably withheld, except as required by law.

                                    ARTICLE 7

                                Other Provisions

     7.01 Benefit and Assignment. This Agreement shall be binding upon and shall
inure to the benefit of the parties hereto and their  respective  successors and
assigns.  No party hereto may voluntarily or  involuntarily  assign such party's
interest  under this  Agreement  without the prior written  consent of the other
parties.

     7.02 Entire  Agreement.  This  Agreement  and the  Schedules  and  Exhibits
referred to herein embody the entire agreement and  understanding of the parties
and  supersede any and all prior  agreements,  arrangements  and  understandings
relating to matters provided for herein.

     7.03 Fees and  Expenses.  Each party  shall be solely  responsible  for all
costs  and  expenses   incurred  by  it  in  connection  with  the  negotiation,
preparation and performance of and compliance with the terms of this Agreement.

     7.04 Risk of Loss. The risk of any loss, damage,  impairment,  confiscation
or  condemnation of any of the Assets from any cause shall be borne by Seller at
all  times  prior  to the  Closing.  If any such  loss,  damage  or  impairment,
confiscation  or  condemnation  occurs,  Seller  shall apply the proceeds of any
insurance policy,  judgment or award with respect thereto to repair,  replace or
restore the Assets as soon as possible.

     7.05  Amendment,  Waiver,  Etc. The  provisions  of this  Agreement  may be
amended or waived only by an instrument  in writing  signed by the party against
which enforcement of such amendment or waiver is sought.  Any waiver of any term
or  condition  of this  Agreement  or any breach  hereof  shall not operate as a
waiver of any other such term,  condition  or breach,  and no failure to enforce
any provision hereof shall operate as a waiver of such provision or of any other
provision hereof.

     7.06 Governing Law. The construction and performance of this Agreement will
be governed in all respects by the laws of the State of Illinois (except for the
choice of law provisions thereof).

     7.07  Notices.  Any notice,  demand or request  required or permitted to be
given under the  provisions  of this  Agreement  shall be in  writing;  shall be
delivered personally, including by means of telecopy, or mailed by registered or
certified mail,  postage prepaid and return receipt  requested;  shall be deemed
given on the date of  personal  delivery  or on the date set forth on the return
receipt;  and shall be delivered or mailed to the addresses or telecopy  numbers
set forth on the first page of this  Agreement  or to such other  address as any
party may from time to time direct, with copies to:

         In the case of Buyer:              Nichols Laboratories, Inc.
         --------------------
                                            1700 South Mt. Prospect Road
                                            Des Plaines, Illinois 60018
                                            Attention: Douglas Lewis

         With copies to:                    Paul F. Schofield
         --------------
                                            Schofield & Varde, LLP
                                            30 W. Monroe St., Ste. 710
                                            Chicago, IL  60603
                                            Facsimile 312-372-1884

         In the case of Seller
         or Avitar:                         Avitar, Inc.
         ---------
                                            65 Dan Road
                                            Canton, MA 02021
                                            Attention:  CFO

         With copies to:                    Dolgenos Newman & Cronin LLP
         --------------
                                            96 Spring Street
                                            New York, NY 10012
                                            Facsimile 212-925-0690
                                            Attention:  Eugene M. Cronin

     7.08 Breach;  Equitable Relief. The parties acknowledge that the Assets and
rights of the  parties  described  in this  Agreement  are unique and that money
damages  alone  for  breach of this  Agreement  would be  inadequate.  Any party
aggrieved  by a breach of the  provisions  hereof  may bring an action at law or
suit in equity to obtain redress,  including  specific  performance,  injunctive
relief or any other available  equitable remedy. Time and strict performance are
of the essence in this Agreement.

     7.10  Counterparts.   This  Agreement  may  be  executed  in  one  or  more
counterparts, each of which will be deemed an original but all of which together
will constitute one and the same instrument.

     7.11  Joint  and  Several  Liability.  All  joint  obligations  under  this
Agreement shall be joint and several obligations.

     IN WITNESS WHEREOF,  the parties have executed this Agreement as of the day
and year first written above.

         BUYER:                             NICHOLS LABORATORIES, INC.
                                              an Illinois Corporation
                                            By:
                                               ---------------------------
                                                  Douglas E. Lewis, President

         SELLER:                            UNITED STATES DRUG TESTING
                                                     LABORATORIES, INC.
                                               an Illinois corporation


                                            By:
                                                 --------------------------
                                                   Peter Phildius, Chairman


                                           AVITAR, INC., a Delaware Corporation


                                            By: ___________________________
                                               Peter Phildius, Chairman & CEO