Preparation of Tissue Sections and Slides for mRNA Hybridization

The first step for a successful in situ hybridization is the fixation of the tissue. This will ensure target nucleic acid retention and preservation of the tissue morphology. Either crosslinking or precipitative fixatives can be used, and a preference for either of the two types of fixative has often been based on the different types of system under investigation (1 –7 ). For hybridization of regulatory peptide mRNA, 4% paraformaldehyde appears to be the most effective, both on tissue blocks and on tissue culture preparations.