Isolating mRNA and Small Noncoding RNAs from Human Sperm

Abstract

The isolation of spermatozoal RNA is a challenging procedure due to the intrinsic heterogeneous population of cells present in the ejaculate and the small quantity of RNA present in sperm. The transcriptome of these gametes includes a wide variety of messenger RNAs (mRNAs), small noncoding RNAs (sncRNAs), and highly fragmented ribosomal RNAs (rRNAs).The protocol described in this chapter to isolate both the mRNA and sncRNA fractions represents years of development towards automation. It combines a guanidinium thiocyanate-phenol-chloroform-based methodology to reduce the content of DNA and a column-based system. Both manual and semi-automated options are described, with preference given to automation for consistent results. A novel quality control procedure has been developed to assess the integrity and purity of the entire population of isolated mRNAs due to the absence of intact rRNAs.