PASSIVE CUTANEOUS ANAPHYLAXIS IN THE GUINEA-PIG WITH RABBIT ANTIBODIES AGAINST SYNTHETIC POLYPEPTIDES.

The reactions of synthetic polypeptides with their antibodies may be followed by passive cutaneous anaphylaxis, but not by the reverse technique. The reactions were optimal when 18 hours elapsed between the injection of the serum and that of the antigen. Materials which were non-immunogenic as followed by the precipitin test, were shown to be non-immunogenic also by PCA technique. The antisera to various synthetic polypeptide antigens cross-reacted with many chemically related polypeptides. As little as 0.12 μg. of antibody could be detected in 1 ml. of diluted antisera by the PCA technique.