The walking dead: is hydroethidine a suitable viability dye for intra-erythrocytic Plasmodium falciparum?
Hydroethidine has been used as a viability dye in various haemoparasites, including Plasmodium species. We compared flow cytometric quantification by hydroethidine and thiazole orange in P. falciparum. Dead parasites that did not develop or replicate exhibited high levels of DNA fragmentation and abnormal microscopic morphology, but were detected as viable ring-stage parasites by hydroethidine. Hydroethidine quantification was similar to thiazole orange, a DNA-binding dye that stains live and dead parasites. Data obtained cast concerns on hydroethidine as a suitable viability dye in P. falciparum and highlight the necessity of proper gating in flow cytometric studies quantifying parasitaemia.
Plasmodium Molecular Research Unit, Department of Molecular Medicine and Haematology, School of Pathology, University of Witwatersrand and National Health Laboratory Service, Wits Medical School, 7 York Road, Parktown, Johannesburg 2193, South Africa. DewaldtEngelbrecht@gmail.com
Dewaldt
D
Engelbrecht
Thérèsa Louise
TL
Coetzer
D000818:Animals; D004396:Coloring Agents / Q000737:chemistry*; D053938:DNA Fragmentation; D005434:Flow Cytometry / Q000379:methods; D059208:Parasite Load; D010617:Phenanthridines / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000502:physiology*; D013194:Staining and Labeling
D004396:Coloring Agents; D010617:Phenanthridines; C058428:hydroethidine