Affinity-immunoadsorbent fractionation of rat anti-streptococcal A carbohydrate antibodies of restricted heterogeneity.

Antisera obtained from selectively bred Sprague-Dawley rats after a primary series of immunization with group A streptococcal vaccine exhibit specific anti-carbohydrate antibodies of restricted heterogeneity. Separation of anti-carbohydrate antibodies was achieved on the basis of differences in the relative binding affinities of the antibodies for an insoluble, hapten (N-acetyl-D-glucosamine) immunoadsorbent. Evaluation of several eluting reagents including hapten, thiocyanate, urea and acid-salt demonstrated the chaotropic ion thiocyanate to be most effective in separating anti-hapten populations of individual affinity characteristics. In general, there was no consistent relationship between the net electrical charge of an antibody and its relative binding affinity for the immunoadsorbent. Furthermore, non-precipitating rat anti-streptococcal A carbohydrate antibodies were characterized as antibodies of relatively low binding affinity for the hapten immunoadsorbent. From a practical point of view, thiocyanate is recommended for the routine elution of anti-carbohydrate antibodies from innumoadsorbents.