(a) Heat map displaying reactivity of commercial antibodies raised against purified virus or recombinant HA on a nitrocellulose array containing recombinant HA proteins, trivalent influenza vaccine (TIV – Fluzone seasonal 2008/2009 vaccine) and U1-A spliceosome protein printed at indicated concentration. Scale bar reflects median fluorescence intensity (MFI) of antibody-bound array features in a and b. H1mAb, ab66189; H1pAb, ab91531; H3 mAb, ab66187 (Abcam); H3 pAb, IA-PAN4-0100 (eEnzyme). (b) Heat maps displaying reactivity of indicated antibodies when incubated on the influenza peptide array. Antibodies are the same as those described in a. (c) Highest reactivity peptides bound by H1pAb and H3pAb. (d) Histogram displaying percent of maximum reactivity of HA antibodies H1pAb and H3pAb cleared and not cleared with selected peptides to recombinant H1, recombinant H3, and Fluzone vaccine antigens. Error bars represent the mean ± SEM of % of maximum MFI of triplicate array features. For each antigen, % of maximum MFI of the highest MFI replicate feature (of three) in the non-pre-cleared condition was calculated.