The unique characteristics of covalently polymerized bovine serum albumin solutions when used as antibody detection media.

Bovine Serum Albumin solutions (BSA) have been chemically polymerized to give solutions (PBSA) with superior serological properties. The new PBSA reagents are shown to contain covalently bonded dimers, trimers, tetramers, and larger polymers, the presence of which is directly related to hemagglutination by IgG antibody. Data are presented which show that reagents containing increased amounts of higher molecular weight polymers enhance hemagglutination, as demonstrated by serum albumin titrations of various antisera. Additionally, isolated polymers are shown to enhance hemagglutination as a function of their molecular weight with the high molecular weight tetramers being more effective than the trimeric form, which in turn is more effective than the dimeric and monomeric forms. The protein concentration does not play any significant role in these events. The data establish that the polymeric content of bovine serum albumin reagents is a major factor in the potentiating properties of such solutions. Additionally, it is shown that these reagents act not only on the second stage of hemagglutination as a function of the bovine albumin present, but also on the first stage of hemagglutination as a function of the ionic strength of these reagents. The polymeric content and ionic strength of albumin solutions are the major criteria in determining the effectiveness of these potentiating reagents.