Separation of Earthworm Coelomocytes by Velocity Sedimentation

Abstract

Earthworm leukocytes (coelomocytes) are heterogeneous morphologically (1,2) and participate in diverse functions including graft rejection (3), phagocytosis (1), formation of rosettes with SRBC (4), and mitogen responsiveness (5,6). Specific cells mediating these responses are controversial, thus we have developed a procedure for separating coelomocytes by velocity sedimentation at unit gravity. This separation technique, widely applicable in mammalian systems, selects cells primarily on the basis of size (7, 8). By this isolation procedure, we have enriched for at least two distinct coelomocytic types, basophils and granulocytes which participate in graft rejection (3). After enriching for distinct coelomocytes, we now have a method for subjecting them to various immunobiological tests.