Accudenz density gradient purification of Plasmodium sporozoites. A. Photographs of a bilayer discontinuous Accudenz density gradient overlayed with P. yoelii sporozoites in RPMI before and after centrifugation. Mosquito debris pellets to the bottom of the gradient, mosquito lipids float to the top of the gradient, and sporozoites accumulate at the bilayer interface. B. Representative DIC images of unpurified and purified sporozoites before and after centrifugation show a significant reduction in mosquito material. Scale bar is 5 microns.