[Application of chromosome painting to analysis of structural aberration in five cases]

This article reports that competitive hybridization using entire chromosome specific libraries as probe and human genomic DNA as the competitor allows intense and specific fluorescent staining of human chromosome in metaphase. This general approach is called "chromosome painting".

The probes comprising chromosomes 2, 5, 6, 7, 13, 14, X specific libraries were used to analyse five cases which had been suspected of subtle translocation and deletion in karyotype analysis by G-banding of metaphase cells. The authors selected entire chromosome-specific DNA libraries hybridizing with the five cases. Unlabeled human genomic DNA was used to inhibit the hybridization of sequences in the library that bind to multiple chromosome.

The target chromosome was made at least 20 times brighter parunit length than the others. Translocations and deletions were detected clearly in metaphase and were consistent with G-banding. However, the result was clearer and the detection easier, compared with G-banding.

Chromosome painting is very powerful for identification of chromosome structural aberrations. Translocation and deletion involving these chromosomes can be strikingly visualized. The hybridization intensity and specificity are such that even very small portions of the involved chromosome can be detected. This technique is especially useful in settings where high-quality banding is difficult.