Reticulocyte invasion is sensitive to chymotrypsin and trypsin treatment.

Reticulocyte-rich blood from normal BALB/c mice was treated with chymotrypsin (1 mg/mL), trypsin (1 mg/mL), or buffer alone, and the invasion rate of P yoelii was measured using the in vivo reticulocyte invasion assay as described in “Materials and methods.” The experiment was performed twice, and the data reported are representative of both experiments. Invasion of reticulocytes was almost eliminated by chymotrypsin and trypsin.