Competitive adsorption of human immunoglobulin G and albumin: consequences for structure and reactivity of the adsorbed layer.

The affinity of polyclonal anti-IgG for human IgG adsorbed on silica surfaces was investigated by two complementary techniques, scanning angle reflectometry and 125I radiotracing. Special attention was paid to compare the reactivity of IgG adsorbed directly or by exchange with already adsorbed albumin. In particular it was shown that (i) in the first case (direct adsorption) the reaction between anti-IgG and adsorbed IgG was in the ratio 1:1 and (ii) in the second case (adsorption by exchange) there was no reaction.