X0303 4 2011-01-11 0 0000353569 QUIDEL CORP /DE/ QDEL 0001021412 SCHULER JACK W 10165 MCKELLAR COURT SAN DIEGO CA 92121 1 0 0 0 Common Stock 2011-01-11 4 A 0 475000 13.15 A 3142288 D The Reporting Person purchased 475,000 common shares at the public offering price of $13.15 in an offering of common shares by the Company. In addition to the shares reported on this Form 4 as directly owned by the Reporting Person, 65,000 shares are held indirectly by the Reporting Person's spouse and 683,843 shares are held indirectly by trusts for the benefit of the Reporting Person's children. The Reporting Person disclaims all beneficial ownership of these shares owned by his spouse and the trusts for the benefit of his children, except to the extent of his pecuniary interest, if any. Robert J. Bujarski, attorney-in-fact for Jack W. Schuler 2011-01-21