Rapid and quantitative detection of unique sequence donor DNA in extracts of cultured mammalian cells: an aid to chromosome mapping.

A rapid and highly sensitive method for screening the human DNA content of hybrid or transfected mammalian cells is described. Transfectants containing as little as 200 kb of otherwise undefined human DNA can be readily detected in a background of mouse chromatin. At the highest stringency, single-copy sequences can be detected. Large numbers of independent gene-transfer products are easily screened, making the method ideally suited to the identification of rare, but otherwise unselectable, events. The method does not rely upon the expression of the gene sequence of interest; the sole proviso is the availability of an appropriate DNA probe for the chromosomal region or locus of interest.