Separation of gametocytes of Leucocytozoon smithi from whole peripheral turkey blood.

A technique that uses a Ficoll density-gradient system was devised for isolating gametocytes of the parasitic blood protozoan Leucocytozoon smithi from whole turkey blood. Turkey blood containing gametocytes was layered onto a 35% solution of Ficoll and centrifuged. A white band, containing gametocytes and leukocytes, was observed just below the Ficoll-plasma interphase, clearly separated from the underlying packed erythrocytes. The gametocyte-leukocyte suspension was then subjected to a second centrifugation on a continuous gradient of Ficoll ranging from 12% at the top of the tube to 35% at the bottom. The second centrifugation separated the white cells containing the gametocytes into 5 distinct layers: 1) thrombocytes; 2) gametocytes of L. smithi; 3) lymphocytes; 4) a band of monocytes; and 5) granulocytes. Recovered gametocytes, stored at 4 C in a sterile balanced salt solution, retained their morphological integrity for a minimum of 4 weeks.