Schizont-infected cell enrichment in rodent malaria.

Mouse erythrocytes parasitized with Plasmodium berghei or Plasmodium yoelii were separated by ultracentrifugation using preformed isodensity gradients of the discontinuous type. Three fractions were obtained following centrifugation, the upper of which contained greater than 90% of all schizont-infected cells added to the gradient. The gradient material, Stractan II, is an arabinogalactan polysaccharide and appears to yield results similar to those available using gradients of bovine serum albumin. Cells are not altered morphologically or physiologically (as assessed by infectivity) by the treatment.