Human sperm DNA is an important genetic and
epigenetic material, whose
chromatin structure differs from that of somatic
cells. As such, conventional
methods for
DNA extraction of somatic
cells may not be suitable for obtaining
sperm DNA. In this study, we evaluated and compared three
sperm DNA extraction
techniques, namely, modified
guanidinium thiocyanate
method (
method A), traditional
phenol-
chloroform method (
method B), and TianGen kit
method (
method C).
Spectrophotometry and
agarose gel electrophoresis analyses showed that
method A produced
DNA with higher quantity and purity than those of
methods B and C (P<0.01).
PCR results revealed that
method A was more reliable in amplifying DEAD-box
polypeptide 4 (DDX4) and copy number variations (CNVs) than
methods B and C, which generated false-positive errors. The results of
sperm DNA methylation assay further indicated that
methods A and B were effective, and the former yielded higher quantitative accuracy. In conclusion, the modified
guanidinium thiocyanate
method provided high quality and reliable results and could be an optimal
technique for extracting
sperm DNA for
methylation assay.