Abstract
The requirement for heat-labile [human] opsonins for phagocytosis of 2 serologically distinct strains and a number of clinical isolates of C. albicans was examined by a radiometric technique. Both strains and all 10 isolates of C. albicans examined apparently required heat-labile opsonins for maximal phagocytosis. Heat-labile opsonins may play an important role in immunity to C. albicans. Some strains of C. albicans may not utilize heat-labile opsonins.