H1N1 Western blotting of PEG precipitates from two healthy adult control samples, healthy adult sera, PBS as a negative control and flu vaccine as a positive control, showed that PEG can precipitate in vitro ICs.

Lane one is the Precision Plus protein standard ranging from 31 to 460 kDa. Three μg of protein per lane was loaded on a 3–8% Tris-acetate denaturing SDS-PAGE gel, blotted to nitrocellulose membrane and incubated with rabbit anti-H1N1 influenza A virus (primary antibody), goat anti-rabbit Immunoglobulin HRP (secondary antibody) and stained using the ECL kit. D stands for Donor, V for Vaccine and Negative control (Lane 7) is PEG with PBS. Lane 15 is a positive control, the influenza vaccine.