Comparison between propidium iodide and 7-amino-actinomycin-D for viability assessment during flow cytometric analyses of the human sperm acrosome

Authors


Nadia Falzone, Department of Biomedical Science, Tshwane University of Technology, Private Bag X680, Pretoria, 0001, South Africa.
Tel.: +27123826342;
Fax: +27123826262
E-mail: falzonen@tut.ac.za

Summary

Evaluation of the acrosome reaction can shed light on the fertilising competence of spermatozoa. To eliminate false-positive results when evaluating the acrosome status of human sperm cells, two viability probes propidium iodide (PI) and 7-amino-actinomycin D (7-AAD) were compared for their ability to stain nonviable cells post-fixation and permeabilisation. Both the mean fluorescence and % dead cells differed significantly with time (P < 0.0001). Unlike PI, 7-AAD did not leach from cells and fluorescence remained stable for up to 4 h. Furthermore, 7-AAD proved to be a proficient marker to exclude dead sperm cells during flow cytometric evaluation of ionophore-induced acrosome reaction.

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