13G

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934
(Amendment No.1 )*

Quidel Corporation
(Name of Issuer)

Common Stock, $.001 Par Value
(Title of Class of Securities)

74838J101
(CUSIP Number)

Check the following box if a fee is being paid with this statement [ ]. (A fee is not required only if the filing person: (1) has a previous statement on file reporting beneficial ownership of more than five percent of the class of securities described in Item 1; and (2) has filed no amendment subsequent thereto reporting beneficial ownership of five percent or less of such class.) (See Rule 13d-7.)

* The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosure provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (However, see the Notes).

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

CUSIP No. 74838J101

l) Name of Reporting Persons
S.S. or I.R.S. Identification Nos. of Persons

2) Check the appropriate box if a Member of a Group (See Instructions)

3) SEC Use Only

4) Citizenship or Place of Organization:

Number of shares Beneficially Owned by Each Reporting Person With:

9) Aggregate Amount Beneficially Owned by Each Reporting Person

10) Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares (See instructions) [ ]

11) Percent of Class Represented by Amount in Row (9):

14) Type of Reporting Person

*Although Kopp Investment Advisors, Inc. exercises investment discretion as to these shares, it is not the owner of them.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

CUSIP No. 74838J101

l) Name of Reporting Persons
S.S. or I.R.S. Identification Nos. of Persons

2) Check the appropriate box if a Member of a Group (See Instructions)

3) SEC Use Only

4) Citizenship or Place of Organization:

Number of shares Beneficially Owned by Each Reporting Person With:

9) Aggregate Amount Beneficially Owned by Each Reporting Person

10) Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares (See instructions) [ ]

11) Percent of Class Represented by Amount in Row (9):

14) Type of Reporting Person

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

CUSIP No. 74838J101

l) Name of Reporting Persons
S.S. or I.R.S. Identification Nos. of Persons

2) Check the appropriate box if a Member of a Group (See Instructions)

3) SEC Use Only

4) Citizenship or Place of Organization:

Number of shares Beneficially Owned by Each Reporting Person With:

9) Aggregate Amount Beneficially Owned by Each Reporting Person

10) Check Box if the Aggregate Amount in Row (9) Excludes Certain Shares (See instructions) [ ]

11) Percent of Class Represented by Amount in Row (9):

14) Type of Reporting Person

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

Item 1(a). Name of Issuer.

Item 1(b). Address of Issuer's Principal Executive Offices.

Item 2(a). Name of Person Filing.

Item 2(b),2(c),2(d), and 2(e). Address of Principal Business Office; Citizenship; Title of Class of Securities; CUSIP Number.

Item 3.

Item 4. Ownership as of 11/30/01:

Item 5. Ownership of Five Percent or Less of a Class.

Item 6. Ownership of More than Five Percent on Behalf of Another Person.

Item 7. Identification and Classification of the Subsidiary which Acquired the Security Being Reported on By the Parent Holding Company.

Item 8. Identification and Classification of Members of the Group.

Item 9. Notice of Dissolution of Group.

Item 10. Certification.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired in the ordinary course of business and were not acquired for the purpose of and do not have the effect of changing or influencing the control of the issuer of such securities and were not acquired in connection with or as a participant in any transaction having such purposes or effect.

Signature.

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: 12/05/01


KOPP INVESTMENT ADVISORS, INC.

By:


John P. Flakne, Chief Financial Officer

AGREEMENT

The undersigned hereby agrees that the Statement on Schedule 13G to which this Agreement is attached be filed on behalf of Kopp Investment Advisors, Inc., a Minnesota corporation; Kopp Holding Company, a Minnesota corporation, of which Kopp Investment Advisors, Inc. is a wholly-owned subsidiary; and LeRoy C. Kopp, who holds 100% of the outstanding capital stock of Kopp Holding Company.

Dated: 12/05/01


KOPP INVESTMENT ADVISORS, INC.

By:


LeRoy C. Kopp
Title: President


LeRoy C. Kopp

KOPP HOLDING COMPANY

By:


LeRoy C. Kopp, President