CATCH-LINKER PLUS PCR LABELING - A SIMPLE METHOD TO GENERATE FLUORESCENCE IN-SITU HYBRIDIZATION PROBES FROM YEAST ARTIFICIAL CHROMOSOMES

A simple and efficient method to generate hapten-labeled DNA fragments from a trace amount of YAC DNA isolated by PFGE is described. After a garase digestion of the gel slice containing the resolved YAC recombin ant, the purified DNA is digested with Scru3Al and a compatible CL oli gonucleotide duplex ligated on. A probe is generated by PCR amplificat ion using a primer complementary to the CL with a single biotin moiety incorporated at the 5' end. When used as a FISH probe, this material yields mapping results superior to Ali-PCR or whole YAC labeling metho ds and allows sensitive detection of chimerism.