Membrane preparations from Plasmodium yoelii -infected RBCs contain unique parasite proteins. Animals were infected with P. yoelii 17X and infected RBCs were collected. (A). Proteins associated with the membranes of uninfected (lane 1) or P. yoelii 17X infected erythrocytes (lane 2) or with intracellular P. yoelii 17X parasites (lane 3) were separated by SDS-PAGE and stained with Coomassie Blue. (B). To evaluate the ability to separate the Py RMPs from parasite associated proteins, isolated protein fractions were separated as in A, blotted onto nitrocellulose and probed with rabbit anti-mouse Py MSP8 polyclonal sera. Py MSP8 is a GPI-anchored membrane protein of P. yoelii trophozoites and merozoites. Normal rabbit sera (NRS) served as a negative control. Molecular weights in kiloDaltons (kDa) are indicated.