Figure 3. Purity control experiment of the intracellular parasite fraction.
After an overnight intracellular growth within HFF cells, parasites were collected by scraping the monolayer and were mechanically released from host cells by sequential passage through 20, 23, 25 and 27G needles. Parasites were further purified through a column of silicon-treated glass wool. (A) Western-blot analysis of the parasite fraction before (−) and after (+) filtration; detection of host cell membranes was done using the anti-HsTfR (α-HsTfR) mAb H68.4. Protein extracts correspond to 107 (1), 106 (2) and 105 (3) parasites. The α-TgSAG1 antibody that is directed against the T. gondii major surface protein SAG1 was used as an internal control of protein load in each lane. (B) IF microscopy of the PV membrane protein GRA5 (α-TgGRA5) in the same fractions before and after filtration.