The fractionation procedure yields primarily the immunoglobulin fraction of antiserum. To ensure specificity the fractionated antiserum is adsorbed using solid phase techniques, if necessary. Rabbit Anti-Protein A is lyophilized from 0.01 M phosphate buffered saline, pH 7.2, to which no preservatives have been added. Identity and purity of the antibody is established by immunoelectrophoresis. Electrophoresis of the antibody preparation followed by diffusion versus anti-rabbit IgG results in a single arc of precipitation and versus anti-rabbit whole serum results in multiple arcs of precipitation.
