RAPID CHROMOSOME IDENTIFICATION BY OLIGONUCLEOTIDE-PRIMED IN-SITU DNA-SYNTHESIS (PRINS)

We describe a method for rapid identification of chromosomes at metaph ase, and quantification of chromosomes in interphase, by annealing oli gonucleotide primers, derived from chromosome-specific subsets of repe ated DNA families, to the DNA of cytological preparations, and enzymat ic extension with the incorporation of labelled nucleotides. The metho d is equally applicable to normal cells or those from somatic cell hyb rids. Where the labelled product is too small or of too low a copy num ber to be readily seen after the single extension reaction, we have de veloped a method for cyclic amplification of the labelled DNA, enablin g clear visualization of the signal.