To facilitate the transfer of technology from the research laboratory to the clinical laboratory, pathologists and clinicians must become familiar with the tools of molecular biology. In this report, two such research techniques, in situ and Northern hybridizations, are reviewed. Also, how each may be used and adapted for the good of the patient is considered. Both methods can be applied to clinical material, but both require a good deal of technical expertise. Commercial development of these assays will facilitate their introduction into the clinical laboratory.