A novel semi-automated in situ hybridisation protocol for microRNA detection in paraffin embedded tissue sections

MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression by binding to complementary sequences on target messenger RNA transcripts. In situ hybridisation (ISH) methods have been applied to the study of miRNA in tissue samples in order to understand which is the source of the miRNA of interest. In this paper, the authors describe a novel semi-automated bright field ISH method to visualise miRNAs in formalin fixed paraffin embedded tissue sections. The relevance of this work resides in the use of 3,3'-diaminobenzidine and peroxidase as the detection method, which provides a good defined deposition within tissues This method, which reveals the cells of origin of specific miRNAs, will enable investigators to further explore the biological role of miRNAs.