Murine Malaria Infection Protocol

The mice infected by P. berghei and with different levels of parasitemia were used as donor mice. The donor mice's parasitemia level was first determined from their blood that is obtained by cutting (0.5 to 1 mm section) the tail of the mice using scissors [47 (link)]. To inoculate and infect the study animals, the donor mouse with a parasitemia of 30 up to 37% [48 ] was sacrificed by a head blown technique, and blood was drained into a test tube containing anticoagulant (3.8% trisodium citrate (BDH Chemicals, England)) through the incision of the jugular vein. The collected blood was then diluted in normal saline to obtain 1 × 10⁷ infected red blood cells (RBCs) in every 0.2 ml suspension [49 (link)]. The dilution was done based on the erythrocyte count of the normal mice and parasitemia of the donor mice in such a way that 1 ml blood contains 5 × 10⁷ infected RBCs [47 (link), 50 (link)]. Therefore, each mouse used was infected by 0.2 ml P. berghei-infected blood (1 × 10⁷ parasitized RBCs) intraperitoneally.