[Assignment of differentiation-relevant cDNA RA538 on human chromosomes by fluorescence in situ hybridization].

OBJECTIVE

To localize the differentiation-relevant cDNA RA538 (3.8kb) onto the human chromosome 8q2.

METHODS

A modified non-isotopic labeling technique was used.

RESULTS

The cDNA RA538 was obtained by subtraction hybridization from human esophageal cancer cell line EC8712 induced by retinoic acid. Fluorescence in situ hybridization (FISH) using double-labeled probes showed clear and paired hybridization signals at the corresponding regions of both two chromatids in 18 out of 60 metaphases examined. While by single-labeling, only 7 were positive in 60 metaphases observed and the fluorescent spots were seen only at one chromatid.

CONCLUSION

The modified FISH protocol is useful for mapping cDNA sequences of a few kilobases.