ALTERATIONS IN BRAIN-TUMOR DNA DETECTED BY A FINGERPRINTING PROBE

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