Prepared by MERRILL CORPORATION
QuickLinks -- Click here to rapidly navigate through this document
    Filed Pursuant to Rule 424(b)(3)
Registration No. 333-59390

Prospectus Supplement No. 2
to
Prospectus Dated October 24, 2001

QUIDEL CORPORATION

         LOGO


2,486,514 Shares of Common Stock of Quidel Corporation

        The following information supplements, and must be read in connection with, the information contained in the prospectus, dated October 24, 2001 (the "Prospectus"), of Quidel Corporation, a Delaware corporation. This Prospectus Supplement must be delivered with a copy of the Prospectus. All capitalized terms not otherwise defined herein have the respective meanings ascribed to them in the Prospectus. The following information replaces in its entirety the information provided in the Prospectus under the caption "Selling Stockholders".

The date of this Prospectus Supplement No. 2 is January 31, 2002.

SELLING STOCKHOLDERS

        The shares of our common stock covered by this prospectus were issued to former shareholders and certain option holders of Litmus, in a transaction in which Litmus became a wholly owned subsidiary of ours. In a series of private transactions, we issued approximately 3,250,000 shares of our common stock to former shareholders and certain option holders of Litmus, pursuant to the terms of the merger agreement between us and Litmus. Almost all of these shares were prohibited from being sold until June 6, 2001, pursuant to lock-up agreements executed by us and certain of the selling stockholders. Of these shares, 2,486,514 shares are the subject of this prospectus. The remaining 763,486 shares issued in connection with the merger are subject to an escrow agreement as security against breaches of certain representations and warranties made by Litmus. Of these escrowed shares, 32,580 have been released to us from escrow, due to a cash payment made by us to a third party on behalf of Litmus for financial advisory fees, and 730,906 remain in escrow. Under a registration rights agreement dated December 8, 2000, we agreed to register the shares that were not placed in escrow and maintain the effectiveness of the registration statement until the earlier of one year from effectiveness or the date on which all the shares covered by this prospectus have been sold. For more information on distribution of the shares, see "Plan of Distribution" on page 16 of this Prospectus. The selling stockholders may from time to time offer and sell pursuant to this Prospectus, any or all of the 2,486,514 shares of our common stock. The table below describes, on or prior to January 15, 2002, the number of shares of our common stock covered by this prospectus that each selling stockholder beneficially owns. The term "selling stockholders" includes the holders listed below and their transferees, pledgees, donees or other successors. We have prepared this table based upon information furnished to us by or on behalf of the selling stockholders.

        The selling stockholders confirmed at the time they acquired the shares listed below that they acquired the shares for investment purposes only and not with a view toward their resale, and acknowledged the existence of restrictions on resale that apply to these shares. This offering relates only to the sale of shares held or to be held by the selling stockholders named in the following table. Since the date on which they provided us with the information below, the selling stockholders may have


sold, transferred or otherwise disposed of some or all of their shares of our common stock in transactions exempt from the Securities Act's registration requirements.

 
   Shares Beneficially Owned Prior to Offering(1)
    
   Shares Beneficially Owned if All Shares Being Registered Are Sold(3)
  
Selling Stockholders
   Number of
Shares
   Percent(2)
   Number of Shares
Being Registered
For Sale
   Number of
Shares
   Percent(2)
  
Mary Lynne Ament   3,684   *   2,847   837   *  
Terrence Andreasen   5,577   *   4,310   1,267   *  
Jason Barzilay   3,928   *   3,036   892   *  
Beacon Fiduciary Advisors, Inc.   73,673   *   56,937   16,736   *  
Alison P. Bisno   3,684   *   2,847   837   *  
Alexander Blass   1,964   *   1,518   446   *  
Constance Blass O'Neill Trust #3   7,367   *   5,694   1,673   *  
Constance Blass O'Neill, Trustee for Amanda Beverly O'Neill   2,947   *   2,278   669   *  
Constance Blass O'Neill, Trustee for Isabel Leaman O'Neill   2,947   *   2,278   669   *  
Constance Blass O'Neill, Trustee for John Blass O'Neill   2,947   *   2,278   669   *  
Constance Blass O'Neill, Trustee for Kristen Patricia O'Neill   2,947   *   2,278   669   *  
Gus Blass II   80,538   *   62,242   18,296   *  
Gus Blass III   22,190   *   17,149   5,041   *  
Gus Blass III Keough Account   36,836   *   28,468   8,368   *  
Patricia B. Blass   7,367   *   5,694   1,673   *  
Rebecca Blass   982   *   759   223   *  
Charlotte & Curt Bradbury   3,684   *   2,847   837   *  
Marian B. Buccafurni   319,617 4 1.14 % 247,009 4 72,608   *  
Marian Buccafurni & Paul Lawrence   3,684   *   2,847   837   *  
Harriet Calhoun Stephens Trust   2,211   *   1,709   502   *  
Capital Properties, Ltd.   85,088   *   65,759   19,329   *  
C.E. Unterberg, Towbin LLC   4,910   *   3,795   1,115   *  
John Chan & Lily W. Chan   3,684   *   2,847   837   *  
William H. Chan, MD   14,735   *   11,388   3,347   *  
William H. Chan, MD & Janet Wong, DDS   8,840   *   6,832   2,008   *  
Aulena Chaudhuri   4,169   *   3,222   947   *  
Sally Chew   7,367   *   5,694   1,673   *  
Betsy Cohen   6,098   *   4,713   1,385   *  
CooperSurgical Acquisition Corp.   1,473,453   5.28 % 1,138,725   334,728   1.19 %
Coral Partners   3,684   *   2,847   837   *  
Coral Two Corporation   11,051   *   8,541   2,510   *  
Steve Costella   540   *   417   123   *  
Eric Daniel   3,684   *   2,847   837   *  
Peter Davis   15,750   *   12,172   3,578   *  
Lou De Amicis   4,065   *   3,141   924   *  
Alan Dror, MD   10,020   *   7,743   2,277   *  
William W. R. Elder   3,684   *   2,847   837   *  

2

Webb J. Engman & Marie J. Engman   1,179   *   911   268   *  
Douglas Engman Fires & Patricia J. Fires   1,179   *   911   268   *  
Leroy Fong & Julie Fong   3,684   *   2,847   837   *  
Donald Freedlander   3,684   *   2,847   837   *  
Regina Gindin   5,893   *   4,555   1,338   *  
Richard Giss   1,473   *   1,138   335   *  
Robert Giss   1,473   *   1,138   335   *  
Vernon Giss   1,473   *   1,138   335   *  
Warren Giss   1,473   *   1,138   335   *  
Henry & Sheila Gladstone   3,684   *   2,847   837   *  
Carol Green   5,893   *   4,554   1,339   *  
William F. Green   148   *   114   34   *  
Carol Hall   1,220   *   943   277   *  
RMH, III Age 21 Trust   982   *   759   223   *  
WSW Hamilton Age 21 Trust   982   *   759   223   *  
Robert M. Hamilton, Jr.   11,051   *   8,541   2,510   *  
Michealle Havenhill   414   *   320   94   *  
Henry Heines   7,749   *   5,988   1,761   *  
Mark Herrman   7,367   *   5,694   1,673   *  
Gail Highberg   1,584   *   1,224   360   *  
Thomas Ingram   1,964   *   1,518   446   *  
Joan Irwin   737   *   569   168   *  
J. Chasnoff Joint Venture #6   5,893   *   4,554   1,339   *  
Roland Jang   18,928   *   14,628   4,300   *  
Jeffrey Jones   148   *   114   34   *  
Stanley Keller   7,367   *   5,694   1,673   *  
Bill Kirsch   540   *   417   123   *  
The Lampert Irrevocable Trust Julie Bell, Trustee   1,473   *   1,138   335   *  
Roland Lampert   68,470   *   52,915   15,555   *  
Ellen B. Laner Trust   7,367   *   5,694   1,673   *  
Leah Lawrence   4,658   *   3,600   1,058   *  
Paul J. Lawrence   467,974 4,5 1.67 % 306,470 4,5 161,504 5 *  
The Lawrence/Buccafurni 2001 Charitable Life Trust, dated December 27, 2001   150,000   *   150,000   0   *  
Diem Le   28   *   22   6   *  
Sheng Fen Li   330   *   255   75   *  
Peter Ly   5,225   *   4,038   1,187   *  
Douglas H. Martin   2,947   *   2,278   669   *  
Dennis McGee   1,989   *   1,537   452   *  
Robert McGee   148   *   114   34   *  
Glen McLaughlin   19,054   *   14,726   4,328   *  
Glen Wallace McLaughlin   3,684   *   2,847   837   *  

3

MH Fund, Inc.   35,363   *   27,329   8,034   *  
Allen Misher   29,761   *   23,000   6,761   *  
Karen Morrical   1,473   *   1,138   335   *  
Mark Morris   2,434   *   1,881   553   *  
William Muttera   1,220   *   943   277   *  
Teresa M. Nippes   4,065   *   3,141   924   *  
Debbie Nishijima   428   *   331   97   *  
Norman Family Investments LP   4,715   *   3,644   1,071   *  
Rebecca O'Brien   4,269   *   3,299   970   *  
Robert O'Callaghan   589   *   455   134   *  
Constance O'Neill   3,928   *   3,036   892   *  
David M. O'Malley   4,065   *   3,141   924   *  
John O'Malley   73,808   *   57,040   16,768   *  
John A. O'Malley, Jr.   4,065   *   3,141   924   *  
Robert D. O'Malley   4,065   *   3,141   924   *  
Joseph Ogrinc   295   *   228   67   *  
Patrick B. Parmelee   148   *   114   34   *  
Perry O. Parmelee & Joan W. Parmelee, Trustees of the Parmelee Trust U/D/T Dtd 5/24/93   2,211   *   1,709   502   *  
Robert Pena   21   *   16   5   *  
Lawrence S. Phillips   36,836   *   28,468   8,368   *  
Roxane Phillips   1,473   *   1,138   335   *  
Scott Read   1,291   *   998   293   *  
James Reinsch   237   *   183   54   *  
Cynthia Robbins-Roth   1,220   *   943   277   *  
William Rohn   295   *   228   67   *  
Louis Rosen & Vivan B. Rosen   7,367   *   5,694   1,673   *  
Hank Sakai   5,893   *   4,554   1,339   *  
Julie A. Saunders   1,473   *   1,138   335   *  
Heresh Shah   6,098   *   4,713   1,385   *  
Donny Shapiro   186   *   144   42   *  
David Shockey   4,065   *   3,141   924   *  
Ben Simon   3,928   *   3,036   892   *  
Arthur Small, Jr.   5,009   *   3,871   1,138   *  
J. G. Stuckey   1,473   *   1,138   335   *  
David Sutton   3,169   *   2,449   720   *  
Bess Stephens Family Trust   35,363   *   27,329   8,034   *  
Jackson T. Stephens Trust One   20,628   *   15,942   4,686   *  
Warren A. Stephens & Harriet C. Stephens Childrens Trust   3,684   *   2,847   837   *  
Warren A. Stephens, Trustee of the Warren A. Stephens Trust   8,840   *   6,832   2,008   *  
Mya Myat Tun   212   *   164   48   *  
Barry Waxman   3,684   *   2,847   837   *  

4

Gordon A. Wong, MD & Merrily F. Wong   25,785   *   19,927   5,858   *  
Gordon Wong, MD   3,684   *   2,847   837   *  
Elmar Zanflorin   3,684   *   2,847   837   *  
*
Less than 1%.

(1)
Beneficial ownership is determined in accordance with the rules of the Securities and Exchange Commission. Unless otherwise noted, and subject to applicable community property laws, each individual has sole voting and investment power with respect to the shares indicated. Shares of common stock subject to options currently exercisable or exercisable within 60 days after January 15, 2002, are deemed outstanding for computing the share amount and the percentage ownership of the person holding such stock options, but are not deemed outstanding for computing the percentage of any other person.

(2)
Computed based on 27,891,901 shares of common stock outstanding as of January 2, 2002.

(3)
Assumes all of the shares of common stock that may be offered hereunder are sold.

(4)
Includes 150,000 shares held by the Lawrence/Buccafurni 2001 Charitable Life Trust, dated December 27, 2001, with respect to which Mr. Lawrence and Ms. Buccafurni disclaim beneficial ownership. Includes 3,684 shares held jointly by Marian Buccafurni and Paul Lawrence over which Ms. Buccafurni and Mr. Lawrence share voting control.

(5)
Includes 72,500 shares of common stock which may be acquired within 60 days after January 15, 2002, through the exercise of stock options.

5



QuickLinks

Prospectus Supplement No. 2 to Prospectus Dated October 24, 2001