Alterations in brain tumor DNA detected by a fingerprinting probe.

We used a novel DNA fingerprinting probe O-chi-1 (ref. 1) to detect differences in the hybridization pattern of brain tumor DNA and paired normal tissue of a given individual. Representatives of meningiomas (two), glioblastoma multeforme (three) and astrocytoma (one) were studied. Alterations, which included amplification as well as the loss of a normal band in tumor DNA, were observed in four of the six tumours. While the increased intensity of a band can be taken to imply increased copy number, the disappearance of bands could either be due to loss of DNA sequence or rearrangement resulting in different sized bands.