Detection and quantitation of chicken antibodies to streptococcal carbohydrate by high-salt reverse radial immunodiffusion

Abstract

A comparative study was made of the reverse radial immunodiffusion technique and quantitative precipitin analysis for determining the amount of precipitating chicken anti-streptococcal carbohydrate antibodies in ‘high-salt’ buffers. For most immune sera the two techniques gave similar values but with some the reverse radial immunodiffusion technique underestimated the antibody content. In most cases this was correlated with the presence of considerable polymeric (IgM and IgA) immunoglobulin antibody. As little as 45 μg/ml of anti-carbohydrate antibody could be detected using this method. This ‘high-salt’ radial immunodiffusion technique is also useful for detecting chicken antibodies to bovine serum albumin, dinitrophenylated proteins, blood group substances and gamma globulins.