Comparative study on determination of sperm DNA integrity by sperm chromatin dispersion test and by acridine orange staining test

Abstract

Objective To analyze and compare the accuracy and utility of determining sperm DNA integrity by sperm chromatin dispersion (SCD) test and acridine orange staining (AO) test.Methods The level of DNA fragmentation was determined by SCD test and AO test in 32 adult healthy fertile men and 27 idiopathic oligozoospermia (IO) patients.Sperm nuclei with large DNA dispersion halos or with mediumsized halos were normal and nuclei with small-sized halos or no halo were abnormal.The normal sperm DNA was double strands and stained by AO as green.The damaged sperm DNA was single strand,which were stained as green for native DNA and red for denatured DNA.Results The percentage of sperm nuclei with large halos,medium-sized halos,small-sized halos and no halo evaluated bv SCD test in IO patients were (49.9±13.8)%,(11.5±5.4)%,(11.9±6.1)%and(26.7±10.0)%,and they were(73.2±6.2)%,(14.7±6.3)%,(6.8±2.9)%and(5.3±2.2)%in healthy control group,respectively.There was significant difference between two groups(t=8.576,P＜0.01;t=2.083,P＜0.05;t=4.284,P＜0.01;t=11.823,P＜0.01).The percentage of sperm DNA fragmentation was (38.6±12.1)%in IO patients and was (12.1±5.2)% in fertile men,respectively.A statistically significant difference was found between IO patients and healthy control group under SCD test (t=11.995,P＜0.01).AO test showed no significant differences between IO patients and healthy control group (t=1.626,P＞0.05).The percentage of sperm DNA fragmentation evaluated by AO test in IO patients was (45.5 ±13.8)%,and it was (39.8±13.3)%in healthy control group.Conclusions Sperm DNA fragmentation may lead to male infertility.The SCD is effective in testing the sperm DNA fragmentation as a screening procedure to determine semen quality during basic infertility investigation for clinical use. Key words: Oligospermia; Spermatozoa; DNA damage; Staining and labeling; Genetic techniques