PCR in situ: a rapid alternative to in situ hybridization for mapping short, low copy number sequences without isotopes.

A new technique for rapid localization of short, low copy number sequences is described, which uses a form of PCR on preparations of fixed metaphase chromosomes on microscope slides, with the temperature cycling controlled by a flatbed thermal cycler. In its present form, the method is capable of detecting very low copy number sequences, and further development is expected to achieve the target of localizing unique sequences. It has advantages over conventional fluorescent in situ hybridization, both in the speed (easily complete within a work-day) and in the potential sensitivity.