Parasite Viability Assay

Parasite viability was measured by incubating the treated and control cells in 0.5 mg/ml 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) for 3 h followed by subsequent addition of 100 µl of 0.04 N HCl in isopropyl alcohol. The principle underlying the MTT assay is that living mitochondria convert MTT to a dark blue compound, formazan, which is soluble in acid isopropyl alcohol. Formazan was detected at 570 nm on the microplate reader. The percentage viability was obtained by calculating the ratio of OD values in wells with treated cells versus the wells with controls multiplied by 100 (Miller et al., 2000).