Abstract

Quantitative micro-complement fixation was used to compare human serum albumin with the serum albumins of apes, monkeys, and prosimians. The results are consistent with those obtained by other immunological techniques, and they are consistent with the accepted phylogenetic position of these groups. The method requires much less antigen and antibody is more sensitive to small differences in albumin structure. A large scale survey of species differences in protein structure is possible with less than a milliliter of antiserum.