Chicken thrombocytes. Isolation, serological and functional characterisation using the fluorescence activated cell sorter.

Different procedures for enrichment of peripheral blood leukocytes (PBL) from whole chicken blood have been compared in terms of the percentage yield of lymphocytes and thrombocytes. The yield of thrombocytes was low in the buffy coat cells of heparinised blood, but high in PBL enriched from heparinised blood over a Ficoll-Paque density gradient and in PBL prepared from citrated blood by either technique. The fluorescence activated cell sorter (FACS) has been used to separate thrombocytes from lymphocytes in PBL by sorting of the negative cells after staining with specific anti-T and anti-B cell sera (or anti-immunoglobulin). The sorted cells were more than 99% viable, more than 98% thrombocytes by antigenic and morphological criteria and did not respond in vitro to T and B cell mitogens. Absorption studies on a turkey anti-bursa cell serum (ABST) which is cross-reactive for B cells and thrombocytes (8) indicated that the cross-reactivity is attributable to two (or more) antibody specificities in the serum rather than to one antibody directed at shared determinants on the two cell types.