Determination of Relative Concentrations of Soluble Antigens in Sea Urchin Eggs by Means of Graded Antiserum Absorptions Combined with Agar Diffusion Techniques

摘要

Graded absorptions of antiserum in combination with Oudin's single diffusion technique (6) were used for assaying soluble antigens present in homogenates or extracts of unfertilized eggs and two developmental stages of the sera urchin Paracentrotus lividus . Aliquots of antiserum were absorbed with graded amounts of lyophilized extracts or unextracted total homogenates of the antigenic material. When subsequently tested in Oudin tubes with an antigenic standard as the external reagent, the migration rates of the various antigen-antibody precipitates increased linearly with the amount of absorbant added. From the slopes of the absorption curves so obtained the concentration of antigen in the extracts could be calculated relative to that in the homogenates. Moreover, the content of antigen could be determined in homogenates of different origin (unfertilized eggs and developmental stages). The accuracy and validity of this method were evaluated statistically with regard to one of the antigens. The method proved to be of value for a) checking the efficacy of the extraction of soluble antigens from homogenates, and b) for determining concentrations of antigens in various homogenates without preliminary quantitive extraction.