Exhibit 3.6
                            CERTIFICATE OF AMENDMENT
                          CERTIFICATE OF INCORPORATION
                                       OF
                             MEDTOX SCIENTIFIC, INC.

     MEDTOX  Scientific,  Inc., a corporation  organized and existing  under the
General  Corporation  Law of the State of  Delaware  (the  "Corporation"),  does
hereby certify that:

         The amendment to the  Corporation's  Certificate of  Incorporation  set
forth  in the  following  resolutions  approved  by the  Corporation's  Board of
Directors and stockholders was duly adopted in accordance with the provisions of
section 242 of the General Corporation Laws of the State of Delaware:

         "RESOLVED,  that the Certificate of Incorporation of the corporation be
amended by striking Article FOURTH in its entirety and replacing therefor:

         'FOURTH:  The total  number of  shares of stock  which the  Corporation
shall have  authority  to issue is SEVEN  MILLION FOUR  HUNDRED  FIFTY  THOUSAND
(7,450,000)  shares,  SEVEN MILLION FOUR HUNDRED  THOUSAND  (7,400,000) of which
shall be of a class designated as Common Stock with a par value of FIFTEEN CENTS
($0.15)  per  share  and  FIFTY  THOUSAND  (50,000)  of  which  shall be a class
designated as Preferred  Stock with a par value of ONE DOLLAR ($1.00) per share.
All or any part of the authorized capital stock of the Corporation may be issued
and  sold,  from  time to time by the  corporation,  without  further  action by
stockholders,  for such  consideration (but not less than the par value thereof)
and to such persons and on such terms and  conditions as may, from time to time,
be  fixed  or  determined  by  the  Board  of  Directors.   The  voting  powers,
designations,  preferences,  and  relative,  participating,  optional  or  other
special rights and the qualifications,  limitations or restrictions  thereof, of
the classes of stock of the corporation  which are fixed by this  Certificate of
Incorporation,  and the  authority  vested in the Board of  Directors  to fix by
resolution or resolution  providing for the issue of Preferred  Stock the voting
powers, designations, preferences and relative, participating, optional or other
special rights, and the qualifications,  limitations or restrictions thereof, of
the  shares  of  Preferred  Stock  which  are not  fixed by the  Certificate  of
Incorporation, are as follows:

         1. The  Preferred  Stock may be issued from time to time in one or more
series, each such series to have such distinctive designation or title as may be
fixed by the Board of  Directors  prior to the  issuance of any shares  thereof.
Each such series may differ from every other series  already  outstanding as may
be determined  from time to time by the Board of Directors prior to the issuance
of any shares thereof, in any or all of the following, but in other, respects:

                  (a) The rate of dividend which the Preferred Stock of any such
series shall be entitled to receive,  whether the dividends of such series shall
be cumulative or non-cumulative and, if such dividends shall be cumulative,  the
date from which they shall be cumulative.

                  (b) The right or  obligation,  if any, of the  corporation  to
redeem  shares of  Preferred  Stock of any series and the amount per share which
the  Preferred  Stock of any such series shall be entitled to receive in case of
the redemption thereof, and the right of the corporation, if any, to reissue any
such shares after the same shall have been redeemed.

                  (c) The amount per share which the Preferred Stock of any such
series  shall be  entitled  to  receive  in case of the  voluntary  liquidation,
distribution or sale of assets, dissolution or winding up of the corporation, or
in  case  of the  involuntary  liquidation,  distribution  or  sale  of  assets,
dissolution or winding up of the corporation.

                  (d) The right,  if any, of the holders of  Preferred  Stock of
any such  series to convert  the same into other  classes of stock and the terms
and conditions of such conversion.


                  (e) The voting  power,  if any,  of the  holders of  Preferred
Stock of any such  series,  and the terms and  conditions  under  which they may
exercise such voting power.

     (f) The terms of the sinking fund or fund of similar nature,  if any, to be
provided for the Preferred Stock of any such series.

         The  description  of terms of the  Preferred  Stock of each  series  in
respect of the foregoing  particulars shall be fixed and determined by the Board
of  Directors  by  appropriate  resolution  at or  prior  to  the  time  of  the
authorization of the issue of the original shares of each such series.

         2. In case the stated dividends and the amounts payable on liquidation,
distribution or sale of assets, dissolution or winding up of the corporation are
not paid in full, the  stockholders  of all series of the Preferred  Stock shall
share ratably in the payment of dividends,  including accumulations,  if any, in
accordance  with the same which would be payable on such shares if all dividends
were declared and paid in full and in any  distribution  of assets other than by
way of  dividends,  in  accordance  with the sums which would be payable on such
distribution if all sums payable were discharged and paid in full.

         3. The  holders of the  Preferred  Stock  shall be entitled to receive,
when and as declared by the Board of Directors,  out of funds legally  available
therefor,  preferential  dividends in cash at, but not exceeding the annual rate
fixed for each particular  series.  The holders of the Preferred Stock shall not
be entitled to receive any dividends thereon other than dividends referred to in
this Subdivision 3.

         4. So long as any of the  Preferred  Stock remains  outstanding,  in no
event shall any dividend whatever, whether in cash or other property (other than
shares of Common Stock),  be paid or declared or any distribution be made on the
Common Stock, nor shall any shares of the Common Stock be purchased,  retired or
otherwise  acquired for a consideration  by the corporation  unless (a) the full
dividends  of the  Preferred  Stock  for all  past  dividend  periods  from  the
respective date or then current  quarter-yearly  dividend period shall have been
paid or declared and a sum set apart sufficient for the payment thereof, and (b)
if at any time he corporation is obligated to retire shares of any series of the
Preferred  Stock pursuant to a sinking fund or a fund of a similar  nature,  all
arrears, if any, in respect of the retirement of the Preferred Stock of all such
series shall have been made good.  Subject to the foregoing  provisions  and not
otherwise,  such  dividends  (payable  in cash,  stock or  otherwise)  as may be
determined  by the Board of  Directors  may be  declared  and paid on the Common
Stock from time to time out of the remaining  funds of the  corporation  legally
available therefor, and the Preferred Stock shall not be entitled to participate
in any such dividend, whether payable in cash, stock or otherwise.

         5. In the event of any  liquidation,  distribution  or sale of  assets,
dissolution or winding up of the corporation,  whether voluntary or involuntary,
before any distribution or payment shall be made to the holders of Common Stock,
the holders of the  Preferred  Stock of each series shall be entitled to be paid
in cash the  applicable  liquidation  price per  share  fixed at the time of the
original authorization of issuance of shares of such respective series, together
with a sum in the case of each share of the  Preferred  Stock,  computed  at the
annual  dividend  on such share  because  cumulative  to the date fixed for such
distribution or payment date paid thereon.  If such payment shall have been made
in full to the holders of the Preferred Stock, the remaining assets and funds of
the  corporation  shall be  distributed  among the  holders of the Common  Stock
according to their respective shares.

         6. Subject to the powers, preferences and rights and the qualification,
limitations  and  restrictions  thereof,  with  respect to each class of capital
stock of the  corporation  having any  preference  or  priority  over the Common
Stock,  the  holders  of the Common  Stock  shall  have and  possess  all rights
appertaining  to capital stock of the  corporation.  Holders of Common Stock may
not act by written consent without a meeting."


         "RESOLVED,  that the Certificate of Incorporation of the corporation be
amended by striking  Article  FIFTH,  Section 1, in its entirety  and  replacing
therefor:

     FIFTH:  For the  management  of the  business  and for the  conduct  of the
affairs of the Corporation and in further definition,  limitation and regulation
of the powers of the  Corporation and of its directors and  stockholders,  it is
further provided:

         1. The number of  directors of the  Corporation  shall not be less than
three nor more than twelve, the exact number within said limits to be fixed from
time to time by the vote of a majority  of the  directors  then in  office.  The
Board of Directors  shall be divided  into three  classes,  designated  Class I,
Class II and Class III, as nearly equal in number as  possible,  and the term of
office  of  Directors  of one  class  shall  expire at each  annual  meeting  of
stockholders,  and in all cases as to each Director until his successor shall be
elected and shall qualify or until his earlier resignation, removal form office,
death or  incapacity.  Additional  directorships  resulting  from an increase in
number of  Directors  shall be  apportioned  among the  classes  as  equally  as
possible. The initial term of office of Directors of Class I shall expire at the
annual  meeting of  stockholders  in 2000;  that of Class II shall expire at the
annual meeting in 2001; and that of Class III shall expire at the annual meeting
in 2002;  and in all  cases as to each  director  until his  successor  shall be
elected and shall qualify or until his earlier resignation, removal from office,
death or  incapacity.  At each  annual  meeting  of  stockholders  the number of
Directors  equal to the number of  Directors  of the class whose term expires at
the time of such  meeting  (or,  if  less,  the  number  of  Directors  properly
nominated and qualified for election)  shall be elected to hold office until the
third succeeding annual meeting of stockholders after their election.

         In case of any  vacancies,  by reason of an  increase  in the number of
directors,  resignation or otherwise,  directors to fill such vacancies shall be
elected by a majority of the directors then in office,  and any such director so
elected shall hold office until the next succeeding election of directors in the
Class to which such director is assigned."

     IN WITNESS WHEREOF, MEDTOX Scientific,  Inc. has caused this Certificate to
be signed and  attested by its duly  authorized  officers  this 11th of October,
1999.

                                        MEDTOX Scientific, Inc.




                                        By:________________________
                                        Harry G. McCoy
                                        President


ATTEST:

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Kevin Wiersma