Immunomorphologic characterization of chicken thrombocytes.

Chicken thrombocytes were enriched for immunization by utilizing their strong capacity to adhere to plastic surfaces. The produced rabbit anti-thrombocyte serum ATS 3 reacted by means of the unlabeled antibody enzyme method (PAP) specifically with thrombocytes of fixed chicken-blood smears, but not with lymphocytes or other blood cells. When ATS 3 (substrate diaminobencidinetetra-hydrochloride = DAB) and a 1.1 mixture of an anti-bursa serum and anti-thymus serum (ABS/ATS; substrate 4-chloro-1-naphthol = 4-Cl-1-N) were used simultaneously, thrombocytes revealed the brown color typical for DAB, whereas lymphocytes showed the blue stain of 4-Cl-1-N. The finding of a thrombocyte surface antigen not shared by lymphocytes is regarded as a further proof of the diversity of both cell systems, i.e., for the existence of a genuine thrombocyte system in chickens.