Nuclear chromatin decondensation of human sperm assessed by DNA measurement

A sperm nuclear decondensation ability test using 1% SDS + 6 mM EDTA was used to determine an objective method of quantification of the decondensation process by comparing two different methods of quantification: the usual histological method, after staining by the method of Shoor and classification of the sperm heads into normal heads, doubtful heads, swollen heads, and very swollen heads, and the measurement of the removal of DNA from the extremely swollen spermatozoa. After 5 min of exposure to SDS/EDTA, the percentage of removed DNA was correlated (negatively) to the percentage of normal heads, which assessed the two methods and confirmed that all decondensation results obtained after long periods of treatment with SDS/EDTA can be discarded since spermatozoa can be extremely swollen and disappear.