Sedimentation field-flow fractionation application to Toxoplasma gondii separation and purification

Toxoplasmosis is a worldwide disease caused by Toxoplasma gondii, an intracellular protozoa of micronic size range (4-10 mu m). Its classical purification processes are complex and often associated with low recovery. All investigation procedures concerning this parasite require its isolation and purification from at least the mouse ascitic fluid. For this purpose, a recently developed laboratory technology was used, i.e. sedimentation field-flow fractionation. This chromatographic-like separation technology was demonstrated to be particularly selective for isolation and separation of micron-sized biological particles. Sedimentation field-flow fractionation operated on the steric-hyper-layer mode was used to isolate the parasite from the remanent ascitic contaminants of different origins and from red blood cells. With this technology, 86% recovery with 97% viability was obtained in less than 30 min. (C) 1999 Elsevier Science B.V. All rights reserved.