ISOLATION OF BLOOD-STREAM TRYPANOSOMES BY SEDIMENTATION FIELD-FLOW FRACTIONATION

An alternative procedure to isolate circulating blood trypanosomes is proposed using a recently developed separation method whose characteri stics are similar to chromatography. Field-now fractionation is a fami ly of elution separation methods in which trypanosomes are separated f rom the other blood cells by means of their size density and motility. Separation occurs while cells are flowed in a simple isotonic medium into a ribbonlike channel on which a perpendicular field acting on the species is applied. In the case described here, the field is multigra vitational. Purified trypanosome samples can be obtained from mouse bl ood in 20 min, with 80% recovery. The isolation of trypanosomes from m ouse biological. fluids is shown, as well as the possibility of extend ing this procedure to the diagnosis of human sleeping sickness or catt le trypanosomiasis. (C) 1997 John Wiley & Sons, Inc.