Developments in in situ hybridisation.

In situ hybridisation (ISH) is an established family of closely related methods for the detection and visualisation of specific nucleic acid sequences (DNA, RNA) in tissue sections, cytological preparations and whole organisms. The technique has a history of refinements and applications going back over several decades and is routinely employed in laboratories where visualisation of gene expression directly within the tissue of interest is necessary. This article will focus on ISH methods for the demonstration of messenger RNA (mRNA) and micro RNA (miRNA) in formalin-fixed paraffin-embedded (FFPE) tissues with emphasis on non-radioactive signal detection strategies currently available.