Comparison of transmission electron microscopic studies on CS2 vs CS2ΔPTP1 cell line. (A) Conventional chemical fixation: (a) CS2 parental line. MC (MC) display electron dense membranes and an electron lucent lumen; (b) CS2ΔPTP1 cell line shows globular structures and no long lamellar MC structures (arrows). (B) Equinatoxin II-treated cells with pre-embedding labeling: (a) α-PfPTP1 antibodies or (b) α-REX1 antibodies label the slender MC membranes (arrows) and vesicles (arrowheads) in the CS2 parasite line; (c) α-REX1 or (d) α-SBP1 antibodies label globular structures (arrows) and vesicular structures (arrowheads) in the CS2ΔPTP1 cell line. RBCM, red blood cell membrane. (C) The frozen hydrated samples show MC (arrow) in which the lumen looks similar to the RBC cytoplasm as described earlier.61 The CS2ΔPTP1 cell line shows aggregated globular structures (arrows).
