Abstract
Summary It has been shown that random copolymers of D amino acids (gluala, glu ala tyr) are not antigenic in rabbits or guinea pigs. A hapten coupled to a Damino acid polymer was not immunogenic. This lack of immunogenicity has been ascribed to the inability of unnatural synthetic polymers to be degraded by known enzymes. The interaction of the polymers of D amino acids with antisera against the L forms of the same polymer was detectable only by the PCA reaction. Reasons for the non-immunogenicity of the D polymers and their interactions with antibody have been discussed.