AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON JULY 2, 1998

REGISTRATION NO. 333-50409
================================================================================

SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
------------------------

AMENDMENT NO. 3 TO

FORM S-4
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933
------------------------

BECKMAN COULTER, INC.
(EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

DELAWARE 3826 95-1040600
(STATE OR OTHER JURISDICTION OF (PRIMARY STANDARD INDUSTRIAL (I.R.S. EMPLOYER
INCORPORATION OR ORGANIZATION) CLASSIFICATION CODE NUMBER) IDENTIFICATION NO.)
CALIFORNIA BECKMAN INSTRUMENTS (NAGUABO) INC. 33-0593479
CALIFORNIA HYBRITECH INCORPORATED 33-0680402
DELAWARE SMITHKLINE DIAGNOSTICS, INC. 95-1898957
DELAWARE COULTER CORPORATION 59-1635784
(STATE OR OTHER JURISDICTION OF (EXACT NAME OF REGISTRANT (I.R.S. EMPLOYER
INCORPORATION OR ORGANIZATION) AS SPECIFIED IN ITS CHARTER) IDENTIFICATION NO.)

------------------------

4300 NORTH HARBOR BOULEVARD
FULLERTON, CALIFORNIA 92835
(714) 871-4848
(ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER, INCLUDING
AREA CODE, OF REGISTRANTS PRINCIPAL EXECUTIVE OFFICES)
------------------------

WILLIAM H. MAY
VICE PRESIDENT, GENERAL COUNSEL AND SECRETARY
4300 NORTH HARBOR BOULEVARD
FULLERTON, CALIFORNIA 92835
(714) 871-4848
(NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
INCLUDING AREA CODE, OF AGENT FOR SERVICE)
------------------------

COPIES TO:
BRIAN G. CARTWRIGHT
LATHAM & WATKINS
633 WEST FIFTH STREET, SUITE 4000
LOS ANGELES, CALIFORNIA 90071
(213) 485-1234
------------------------

APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO THE PUBLIC:
As soon as practicable after the effective date of this Registration Statement.

If the securities being registered on this Form are being offered in
connection with the formation of a holding company and there is compliance with
General Instruction G, check the following box. [ ]

If this form is filed to register additional securities for an offering
pursuant to Rule 462(b) under the Securities Act, check the following box and
list the Securities Act registration statement number of the earlier effective
registration statement for the same offering. [ ]

If this form is a post-effective amendment filed pursuant to Rule 462(d)
under the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering. [ ]

THE REGISTRANTS HEREBY AMEND THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANTS
SHALL FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF
THE SECURITIES ACT OF 1933 OR UNTIL THE REGISTRATION STATEMENT SHALL BECOME
EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO SAID SECTION 8(a),
MAY DETERMINE.
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2

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 20. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

The Registrant's Third Restated Certificate of Incorporation provides that
a director of the Registrant shall not be personally liable to the Registrant or
its stockholders for monetary damages for breach of fiduciary duty as a
director, except (i) for any breach of the director's duty of loyalty to the
registrant or its stockholders, (ii) for acts or omissions not in good faith or
which involve intentional misconduct or a knowing violation of law, (iii) under
Section 174 of the Delaware General Corporation Law (the "DGCL"), or (iv) for
any transaction from which the director derived an improper personal benefit.

The Registrant's Third Restated Certificate of Incorporation and Bylaws
provide generally that each person who is or was a director or officer of the
registrant shall be indemnified and held harmless by the registrant to the
fullest extent authorized by the DGCL. Section 145 of the DGCL permits a
corporation, subject to certain limitations, to indemnify any person who was or
is a party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding by reason of the fact that such person is
or was a director, officer, employee or agent of the corporation, or was serving
in any of such capacities for another entity at the request of the corporation,
against expenses (including attorneys' fees), judgments, fines and certain
settlements actually and reasonably incurred by such person.

The Registrant maintains directors' and officers' liability insurance which
covers certain liabilities and expenses of directors and officers of the
Registrant and covers the Registrant for reimbursement of payments to directors
and officers in respect of such liabilities and expenses.

ITEM 21. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.

(a) Exhibits

2.1 Stock Purchase Agreement among Coulter Corporation, the
Stockholders of Coulter Corporation and the Company, dated
as of August 29, 1997 (incorporated by reference to Exhibit
2.1 of the Company's Report on Form 8-K dated November 13,
1997, File No. 001-10109). [Note: Confidential treatment has
been obtained for portions of this document.]
3.1 Third Restated Certificate of Incorporation of the Company,
June 5, 1992 (incorporated by reference to Exhibit 3.1 of
the Company's Annual Report to the Securities and Exchange
Commission on Form 10-K for the fiscal year ended December
31, 1992, File No. 001-10109).
3.2 Amended and Restated By-Laws of the Company, as of November
30, 1994 (incorporated by reference to Exhibit 3.2 of the
Company's Annual Report to the Securities and Exchange
Commission on Form 10-K for the fiscal year ended December
31, 1994, File No. 001-10109).
4.1* Indenture dated as of March 4, 1998 by and between the
Company, The First National Bank of Chicago, as trustee, and
Beckman Instruments (Naguabo) Inc., SmithKline Diagnostics,
Inc., Hybritech Incorporated, Coulter Leasing Corporation
and Coulter Corporation.
4.2* Registration Rights Agreement dated March 4, 1998 by and
between the Company and Merrill Lynch, Pierce, Fenner &
Smith Incorporated, Salomon Brothers Inc, Citicorp
Securities, Inc., Credit Suisse First Boston Corporation,
Morgan Stanley & Co. Incorporated, BancAmerica Roberston
Stephens, First Chicago Capital Markets, Inc. and Goldman,
Sachs & Co.
4.3* Specimen Certificate of 7.10% Debentures Due March 4, 2003
(the "Initial 2003 Notes") (included in Exhibit 4.1 hereto).
4.4* Specimen Certificate of 7.10% Debentures Due March 4, 2003
(the "Exchange 2003 Notes") (included in Exhibit 4.1
hereto).

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4.5* Specimen Certificate of 7.45% Debentures Due March 4, 2008
(the "Initial 2008 Notes") (included in Exhibit 4.1 hereto).
4.6* Specimen Certificate of 7.45% Debentures Due March 4, 2008
(the "Exchange 2008 Notes") (included in Exhibit 4.1
hereto).
5.1* Opinion of Latham & Watkins regarding the validity of the
Exchange Notes.
8.1* Opinion of Latham & Watkins regarding certain federal income
tax matters.
10.1 Credit Agreement dated as of October 31, 1997 by and among
the Company, as Borrower, the Initial Lenders and the
Initial Issuing Banks named therein, and Citicorp USA, Inc.
as Agent (incorporated by reference to Exhibit 10.1 of the
Company's Quarterly Report to the Securities and Exchange
Commission on Form 10-Q for the quarterly period ended
September 30, 1997, File No. 001-10109).
10.2 Guaranty dated as of October 31, 1997 made by each Guarantor
Subsidiary (as defined in the Credit Agreement, Exhibit 10.1
herein) of the Company, in favor of the Lender Parties (as
defined in the Credit Agreement) (incorporated by reference
to Exhibit 10.2 of the Company's Quarterly Report to the
Securities and Exchange Commission on Form 10-Q for the
quarterly period ended September 30, 1997, File No.
001-10109).
10.3 Line of Credit Promissory Note in favor of Mellon Bank,
N.A., dated as of October 6, 1993 (incorporated by reference
to Exhibit 10.21 of the Company's Annual Report to the
Securities and Exchange Commission on Form 10-K for the
fiscal year ended December 31, 1992, File No. 001-10109).
10.4 Loan Agreement (Multiple Advance), dated September 30, 1993,
between Beckman Instruments (Japan) Limited and the
Industrial Bank of Japan, Limited (English translation,
including certification as to accuracy; original document
executed in Japanese) (incorporated by reference to Exhibit
10.21 of the Company's Annual Report to the Securities and
Exchange Commission on Form 10-K for the fiscal year ended
December 31, 1993, File No. 001-10109).
10.5 Term Loan Agreement, dated as of September 30, 1993, between
Beckman Instruments (Japan) Limited and Citibank, N.A.,
Tokyo Branch (incorporated by reference to Exhibit 10.22 of
the Company's Annual Report to the Securities and Exchange
Commission on Form 10-K for the fiscal year ended December
31, 1993, File No. 001-10109).
10.6 Term Loan Agreement, dated as of December 9, 1993, between
Beckman Instruments (Japan) Limited and The Dai-Ichi Kangyo
Bank Limited (English translation, including certification
as to accuracy; original document executed in Japanese)
(incorporated by reference to Exhibit 10.23 of the Company's
Annual Report to the Securities and Exchange Commission on
Form 10-K for the fiscal year ended December 31, 1993, File
No. 001-10109).
10.7 Benefit Equity Amended and Restated Trust Agreement between
the Company and Mellon Bank, N.A., as Trustee, for
assistance in meeting stock-based obligations of the
Company, dated as of February 10, 1997 (incorporated by
reference to Exhibit 10.7 of the Company's Annual Report to
the Securities and Exchange Commission on Form 10-K for the
fiscal year ended December 31, 1997, File No. 001-10109).
10.8 The Company's Executive Incentive Plan, adopted by the
Company in 1996 (incorporated by reference to Exhibit 10 of
the Company's Quarterly Report to the Securities and
Exchange Commission on Form 10-Q for the quarterly period
ended March 31, 1996, File No. 001-10109).
10.9 Amendment No. 1 to the Company's Executive Incentive Plan,
adopted in 1996 (incorporated by reference to Exhibit 10.9
of the Company's Annual Report to the Securities and
Exchange Commission on Form 10-K for the fiscal year ended
December 31, 1996, File No. 001-10109).

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4

10.10 The Company's Annual Incentive Plan for 1997, adopted by the
Company in 1997 (incorporated by reference to Exhibit 10.1
of the Company's Quarterly Report to the Securities and
Exchange Commission on Form 10-Q for the quarterly period
ended June 30, 1997, File No. 001-10109).
10.11 The Company's Incentive Compensation Plan of 1990, amended
and restated April 4, 1997, with amendments approved by
stockholders April 3, 1997 and effective January 1, 1997
(incorporated by reference to Exhibit 10 of the Company's
Quarterly Report to the Securities and Exchange Commission
on Form 10-Q for the quarterly period ended March 31, 1997,
File No. 001-10109).
10.12 Amendment to the Company's Incentive Compensation Plan of
1990 adopted December 5, 1997 (incorporated by reference to
Exhibit 4.1 to Post-Effective Amendment No. 1 to the Form
S-8 Registration Statement filed January 13, 1998,
Registration No. 333-24851).
10.13 The Company's Incentive Compensation Plan, as amended by the
Company's Board of Directors on October 26, 1988 and as
amended and restated by the Company's Board of Directors on
March 28, 1989 (incorporated by reference to Exhibit 10.16
of the Company's Annual Report to the Securities and
Exchange Commission on Form 10-K for the fiscal year ended
December 31, 1989, File No. 001-10109).
10.14 Amendment to the Company's Incentive Compensation Plan,
adopted December 5, 1997 (incorporated by reference to
Exhibit 4.2 to Post Effective Amendment No. 1 to the Form
S-8 Registration statement, filed January 13, 1998,
Registration No. 33-31573).
10.15 Restricted Stock Agreement and Election (Cycle
Two -- Economic Value Added Incentive Plan), adopted by the
Company in 1995 (incorporated by reference to Exhibit 10 of
the Company's Quarterly Report to the Securities and
Exchange Commission on Form 10-Q for the quarterly period
ended September 30, 1995, File No. 001-10109).
10.16 Restricted Stock Agreement and Election (Cycle
Three -- Economic Value Added Incentive Plan), adopted by
the Company in 1996 (incorporated by reference to Exhibit
10.15 of the Company's Annual Report to the Securities and
Exchange Commission on Form 10-K for the fiscal year period
ended December 31, 1996, File No. 001-10109).
10.17 Form of Restricted Stock Agreement, dated as of January 3,
1997, between the Company and certain of its Executive
Officers and certain other key employees (incorporated by
reference to Exhibit 10.1 of the Company's Quarterly Report
to the Securities and Exchange Commission on Form 10-Q for
the quarterly period ended June 30, 1997, File No.
001-10109).
10.18 Beckman Instruments, Inc. Supplemental Pension Plan, adopted
by the Company October 24, 1990 (incorporated by reference
to Exhibit 10.4 of the Company's Annual Report to the
Securities and Exchange Commission on Form 10-K for the
fiscal year ended December 31, 1990, File No. 001-10109).
10.19 Amendment 1995-1 to the Company's Supplemental Pension Plan,
adopted by the Company in 1995, effective as of October 1,
1993 (incorporated by reference to Exhibit 10.17 of the
Company's Annual Report to the Securities and Exchange
Commission on Form 10-K for the fiscal year ended December
31, 1996, File No. 001-10109).
10.20 Amendment 1996-1 to the Company's Supplemental Pension Plan,
dated as of December 9, 1996 (incorporated by reference to
Exhibit 10.18 of the Company's Annual Report to the
Securities and Exchange Commission on Form 10-K for the
fiscal year ended December 31, 1996, File No. 001-10109).
10.21 Stock Option Plan for Non-Employee Directors (Amended and
Restated effective as of August 7, 1997), (incorporated by
reference to Exhibit 4.1 of the Company's Registration
Statement on Form S-8 filed with the Securities and Exchange
Commission on October 8, 1997, Registration No. 333-37429).

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10.22 Form of Change in Control Agreement, dated as of May 1,
1989, between the Company, certain of its Executive Officers
and certain other key employees (incorporated by reference
to Exhibit 10.34 of the Company's Annual Report to the
Securities and Exchange Commission on Form 10-K for the
fiscal year ended December 31, 1989, File No. 001-10109).
10.23 Agreement Regarding Retirement Benefits of Arthur A.
Torrellas, adopted December 1, 1993 and dated December 20,
1993, between the Company and Arthur A. Torrellas
(incorporated by reference to Exhibit 10.24 of the Company's
Annual Report to the Securities and Exchange Commission on
Form 10-K for the fiscal year ended December 31, 1993, File
No. 001-10109).
10.24 Amendment to the December 1, 1993 Agreement Regarding
Retirement Benefits of Arthur A. Torrellas, dated as of May
30, 1995, between the Company and Arthur A. Torrellas
(incorporated by reference to Exhibit 10.2 of the Company's
Quarterly Report to the Securities and Exchange Commission
on Form 10-Q for the quarterly period ended June 30, 1995,
File No. 001-10109).
10.25 Second Amendment to the December 1, 1993 Agreement Regarding
Retirement Benefits of Arthur A. Torrellas, dated as of
December 16, 1996, between the Company and Arthur A.
Torrellas (incorporated by reference to Exhibit 10.24 of the
Company's Annual Report to the Securities and Exchange
Commission on Form 10-K for the fiscal year ended December
31, 1996, File No. 001-10109).
10.26 Third Amendment to the December 1, 1993 Agreement Regarding
Retirement Benefits of Arthur A. Torrellas, dated as of July
18, 1997, between the Company and Arthur A. Torrellas
(incorporated by reference to Exhibit 10.26 of the Company's
Annual Report to the Securities and Exchange Commission on
Form 10-K for the fiscal year ended December 31, 1997, File
No. 001-10109).
10.27 Agreement Regarding Retirement Benefits of Albert Ziegler,
dated June 16, 1995, between the Company and Albert Ziegler
(incorporated by reference to exhibit 10.22 of the Company's
Annual Report to the Securities and Exchange Commission on
Form 10-K/A for the fiscal year ended December 31, 1995,
File No. 001-10109).
10.28 Agreement Regarding Retirement Benefits of Fidencio M.
Mares, adopted and dated April 30, 1996, between the Company
and Fidencio M. Mares (incorporated by reference to Exhibit
10.3 of the Company's Quarterly Report to the Securities and
Exchange Commission on Form 10-Q for the quarterly period
ended June 30, 1996, File No. 001-10109).
10.29 Amendment 1997-1 to the Company's Employees' Stock Purchase
Plan, adopted effective January 1, 1998 and dated October
20, 1997 (incorporated by reference to Exhibit 10.3 of the
Company's Quarterly Report to the Securities and Exchange
Commission on Form 10-Q for the quarterly period ended
September 30, 1997, File No. 001-10109).
10.30 The Company's Executive Deferred Compensation Plan,
effective January 1, 1998, dated November 5, 1997
(incorporated by reference to Exhibit 10.4 of the Company's
Quarterly Report to the Securities and Exchange Commission
on Form 10-Q for the quarterly period ended September 30,
1997, File No. 001-10109).
10.31 The Company's Executive Restoration Plan, effective January
1, 1998, dated November 5, 1997 (incorporated by reference
to Exhibit 10.5 of the Company's Quarterly Report to the
Securities and Exchange Commission on Form 10-Q for the
quarterly period ended September 30, 1997, File No.
001-10109).
10.32 The Company's Amended and Restated Deferred Directors' Fee
Program, amended as of June 5, 1997 (incorporated by
reference to Exhibit 10.6 of the Company's Quarterly Report
to the Securities and Exchange Commission on Form 10-Q for
the quarterly period ended September 30, 1997, File No.
001-10109).

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10.33 Amendment 1997-2 to the Company's Supplemental Pension Plan, adopted as of October 31, 1997
(incorporated by reference to Exhibit 10.7 of the Company's Quarterly Report to the Securities and
Exchange Commission on Form 10-Q for the quarterly period ended September 30, 1997, File No.
001-10109).
10.34 Form of Restricted Stock Award Agreement between the Company and its non-employee Directors, effective
as of October 3, 1997 (incorporated by reference to Exhibit 4.1 of the Company's Registration Statement
on Form S-8 filed with the Securities and Exchange Commission on October 8, 1997, Registration No.
333-37429).
10.35 Form of Stock Option Grant for non-employee Directors (incorporated by reference to Exhibit 4.3 of the
Company's Registration Statement on Form S-8 filed with the Securities and Exchange Commission on
October 8, 1997, Registration No. 333-37429).
10.36 The Company's Employees' Stock Purchase Plan, amended and restated as of November 1, 1996, filed in
connection with the Form S-8 Registration Statement filed with the Securities and Exchange Commission
on December 19, 1995, File No. 33-65155 (incorporated by reference to Exhibit 10.29 of the Company's
Annual Report to the Securities and Exchange Commission on Form 10-K for the fiscal year ended December
31, 1997, File No. 001-10109).
10.37 The Company's Option Gain Deferral Program, dated January 14, 1998 (incorporated by reference to
Exhibit 4.2 of Post-Effective Amendment No. 1 to the Form S-8 Registration Statement filed with the
Securities and Exchange Commission on January 13, 1998, Registration No. 333-24851).
10.38 Form of Coulter's Special Incentive Plan and Sharing Bonus Plan, assumed by the Company October 31,
1997 (incorporated by reference to Exhibit 10.38 of the Company's Annual Report to the Securities and
Exchange Commission on Form 10-K for the fiscal year ended December 31, 1997, File No. 001-10109).
10.39 Distribution Agreement, dated as of April 11, 1989, among SmithKline Beckman Corporation the Company
and Allergan, Inc. (incorporated by reference to Exhibit 3 to SmithKline Beckman Corporation's Current
Report on Form 8-K filed with the Securities and Exchange Commission on April 14, 1989, File No.
1-4077).
10.40 Amendment to the Distribution Agreement effective as of June 1, 1989 between SmithKline Beckman
Corporation, the Company and Allergan, Inc. (incorporated by reference to Exhibit 10.26 of Amendment
No. 2 to the Company's Form S-1 registration statement, File No. 33-28853).
10.41 Cross-Indemnification Agreement between the Company and SmithKline Beckman Corporation (incorporated by
reference to Exhibit 10.1 of Amendment No. 1 to the Company's Form S-1 registration statement, File No.
33-24572).
11.1 Statement regarding computation of per share earnings (incorporated by reference to Note 1 Summary of
Significant Accounting Policies and Note 13 Earnings Per Share of the Consolidated Financial Statements
of the Company's Annual Report to the Securities and Exchange Commission on Form 10-K for the fiscal
year ended December 31, 1997, File No. 001-10109).
12.1* Statement of Computation of Ratio of Earnings to Fixed Charges.
21.1 Subsidiaries (incorporated by reference to Exhibit 21 of the Company's Annual Report to the Securities
and Exchange Commission on Form 10-K for the fiscal year ended December 31, 1997, File No. 001-10109).
23.1 Consent of KPMG Peat Marwick LLP.
23.2* Consent of Arthur Andersen LLP.
23.3 Consent of KPMG Peat Marwick LLP.
23.4* Consent of Boston Biomedical Consultants, Inc.
24.1* Power of Attorney of Beckman Instruments, Inc.

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25.1* Statement of Eligibility and Qualification (Form T-1) under
the Trust Indenture Act of 1939 of The First National Bank
of Chicago.
27.1 Financial Data Schedule (incorporated by reference to
Exhibit 27 of the Company's Annual Report to the Securities
and Exchange Commission on Form 10-K for the fiscal year
ended December 31, 1997, File No. 001-10109).
99.1* Letter of Transmittal dated , 1998 and certain other
ancillary documents.

- ---------------

* Previously filed.

(b) Financial Statement Schedules:

None.

SCHEDULES OMITTED

Schedules not listed above are omitted because of the absence of the
conditions under which they are required or because the information required by
such omitted schedules is set forth in the financial statements or the notes
thereto.

ITEM 22. UNDERTAKINGS.

(a) The undersigned registrants hereby undertake that insofar as
indemnification for liabilities arising under the Securities Act of 1933, as
amended (the "Act"), may be permitted to directors, officers and controlling
persons of the Registrants pursuant to the foregoing provisions, or otherwise,
the Registrants have been advised that in the opinion of the Securities and
Exchange Commission such indemnification is against public policy as expressed
in the Act and is, therefore, unenforceable. In the event that a claim of
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or the registrant in the successful defense of
any action, suit paid by a director, officer or controlling person of the
registrant in the successful defense of any action, suit or proceeding) is
asserted by such director, officer or controlling person in connection with the
securities being registered, the Registrant will, unless in the opinion of its
counsel the matter has been settled by controlling precedent, submit to a court
of appropriate jurisdiction the question whether such indemnification by it is
against public policy as expressed in the Act and will be governed by the final
adjudication of such issue.

(b) The undersigned registrants hereby undertake to respond to requests for
information that is incorporated by reference into this prospectus pursuant to
Item 4, 10(b), 11, or 13 of this Form, within one business day of receipt of
such request, and to send the incorporated documents by first class mail or
other equally prompt means. This includes information contained in documents
filed subsequent to the effective date of the registration statement through the
date of responding to the request.

(c) The undersigned registrant hereby undertakes to supply by means of a
post-effective amendment all information concerning a transaction, and the
company being acquired involved therein, that was not the subject of and
included in the registration statement when it became effective.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements on Form S-4 and has duly caused this Amendment No. 3 to the
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Fullerton, State of California, on the 2nd day
of July, 1998.

BECKMAN INSTRUMENTS, INC.

By: /s/ WILLIAM H. MAY
------------------------------------
Name: William H. May
Title: Vice President, General
Counsel and Secretary

Pursuant to the requirements of the Securities Act of 1933, as amended, the
registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements of Form S-4 and has duly caused this Amendment No. 3 to the
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of Fullerton, State of California, on the 2nd day
of July, 1998.

BECKMAN INSTRUMENTS (NAGUABO) INC.

By: /s/ WILLIAM H. MAY
------------------------------------
Name: William H. May
Title: Vice President and Secretary

HYBRITECH INCORPORATED

By: /s/ WILLIAM H. MAY
------------------------------------
Name: William H. May
Title: Vice President and Secretary

SMITHKLINE DIAGNOSTICS, INC.

By: /s/ D. K. WILSON
------------------------------------
Name: Dennis K. Wilson
Title: Vice President, Finance

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COULTER CORPORATION

By: /s/ WILLIAM H. MAY
------------------------------------
Name: William H. May
------------------------------------
Title: Vice President and Assistant
Secretary
------------------------------------

Pursuant to the requirements of the Securities Act, this Amendment No. 3 to
the Registration Statement has been signed by the following persons in the
capacities and on the dates indicated:

SIGNATURES TITLE DATE
---------- ----- ----

/s/ LOUIS T. ROSSO* Chairman of the Board, Chief July 2, 1998
- ----------------------------------------------------- Executive Officer and
Louis T. Rosso Director (Principal Executive
Officer)

/s/ JOHN P. WAREHAM* President, Chief Operating July 2, 1998
- ----------------------------------------------------- Officer and Director
John P. Wareham

/s/ D. K. WILSON* Vice President, Finance and July 2, 1998
- ----------------------------------------------------- Chief Financial Officer
Dennis K. Wilson (Principal Financial Officer)

/s/ JAMES T. GLOVER* Vice President and Controller July 2, 1998
- ----------------------------------------------------- (Principal Accounting
James T. Glover Officer)

/s/ HUGH K. COBLE* Director July 2, 1998
- -----------------------------------------------------
Hugh K. Coble

/s/ CAROLYN K. DAVIS* Director July 2, 1998
- -----------------------------------------------------
Carolyn K. Davis, Ph.D.

/s/ PETER B. DERVAN* Director July 2, 1998
- -----------------------------------------------------
Peter B. Dervan

/s/ DENNIS C. FILL* Director July 2, 1998
- -----------------------------------------------------
Dennis C. Fill

/s/ CHARLES A. HAGGERTY* Director July 2, 1998
- -----------------------------------------------------
Charles A. Haggerty

/s/ GAVIN S. HERBERT* Director July 2, 1998
- -----------------------------------------------------
Gavin S. Herbert

/s/ WILLIAM N. KELLEY* Director July 2, 1998
- -----------------------------------------------------
William N. Kelley, M.D.

/s/ FRANCIS P. LUCIER* Director July 2, 1998
- -----------------------------------------------------
Francis P. Lucier

II-8
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SIGNATURES TITLE DATE
---------- ----- ----

/s/ C. RODERICK O'NEIL* Director July 2, 1998
- -----------------------------------------------------
C. Roderick O'Neil

/s/ BETTY WOODS* Director July 2, 1998
- -----------------------------------------------------
Betty Woods

* Signed by William H. May under Power of Attorney, July 2, 1998.

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11

BECKMAN INSTRUMENTS (NAGUABO) INC.

Pursuant to the requirements of the Securities Act, this Amendment No. 3 to
the Registration Statement has been signed by the following persons in the
capacities and on the dates indicated:

SIGNATURES TITLE DATE
---------- ----- ----

/s/ JOHN P. WAREHAM* President (Principal July 2, 1998
- ----------------------------------------------------- Executive Officer)
John P. Wareham

/s/ PAUL GLYER* Treasurer (Principal July 2, 1998
- ----------------------------------------------------- Financial Officer)
Paul Glyer

/s/ JAMES T. GLOVER* Vice President and Controller July 2, 1998
- ----------------------------------------------------- (Principal Accounting
James T. Glover Officer)

/s/ WILLIAM H. MAY Director July 2, 1998
- -----------------------------------------------------
William H. May

/s/ DENNIS K. WILSON* Director July 2, 1998
- -----------------------------------------------------
Dennis K. Wilson

/s/ GERALD KIRSCHNER* Director July 2, 1998
- -----------------------------------------------------
Gerald Kirschner

* Signed by William H. May under Power of Attorney, July 2, 1998.

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HYBRITECH INCORPORATED

Pursuant to the requirements of the Securities Act, this Amendment No. 3 to
the Registration Statement has been signed by the following persons in the
capacities and on the dates indicated:

SIGNATURES TITLE DATE
---------- ----- ----

/s/ JOHN P. WAREHAM* President and Director July 2, 1998
- ----------------------------------------------------- (Principal Executive Officer)
John P. Wareham

/s/ D. K. WILSON* Vice President, Finance and July 2, 1998
- ----------------------------------------------------- Chief Financial Officer
Dennis K. Wilson (Principal Financial Officer)

/s/ JAMES T. GLOVER* Vice President, Controller July 2, 1998
- ----------------------------------------------------- and Director (Principal
James T. Glover Accounting Officer)

/s/ WILLIAM H. MAY Director July 2, 1998
- -----------------------------------------------------
William H. May

* Signed by William H. May under Power of Attorney, July 2, 1998.

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SMITHKLINE DIAGNOSTICS, INC.

Pursuant to the requirements of the Securities Act, this Amendment No. 3
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated:

SIGNATURES TITLE DATE
---------- ----- ----

/s/ ALBERT ZIEGLER* President (Principal July 2, 1998
- ----------------------------------------------------- Executive Officer)
Albert Ziegler

/s/ D. K. WILSON* Vice President, Finance July 2, 1998
- ----------------------------------------------------- (Principal Financial Officer)
Dennis K. Wilson

/s/ PAUL GLYER* Treasurer (Principal July 2, 1998
- ----------------------------------------------------- Accounting Officer)
Paul Glyer

/s/ JOHN P. WAREHAM* Director July 2, 1998
- -----------------------------------------------------
John P. Wareham

/s/ JAMES T. GLOVER* Director July 2, 1998
- -----------------------------------------------------
James T. Glover

/s/ WILLIAM H. MAY Director July 2, 1998
- -----------------------------------------------------
William H. May

* Signed by William H. May under Power of Attorney, July 2, 1998.

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14

COULTER CORPORATION

Pursuant to the requirements of the Securities Act, this Amendment No. 3
Registration Statement has been signed by the following persons in the
capacities and on the dates indicated:

SIGNATURES TITLE DATE
---------- ----- ----

/s/ EDGAR VIVANCO* President (Principal July 2, 1998
- ----------------------------------------------------- Executive Officer)
Edgar Vivanco

/s/ GENE BABCOCK* Vice President, Finance July 2, 1998
- ----------------------------------------------------- (Principal Financial Officer)
Gene Babcock

/s/ PAUL GLYER* Treasurer (Principal July 2, 1998
- ----------------------------------------------------- Accounting Officer)
Paul Glyer

/s/ JOHN P. WAREHAM* Director July 2, 1998
- -----------------------------------------------------
John P. Wareham

/s/ JAMES T. GLOVER* Director July 2, 1998
- -----------------------------------------------------
James T. Glover

/s/ WILLIAM H. MAY Director July 2, 1998
- -----------------------------------------------------
William H. May

* Signed by William H. May under Power of Attorney, July 2, 1998.

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