Detection of loss of heterozygosity in tumor DNA samples by PCR.

We demonstrate that PCR amplification of human genomic DNA can be used for the detection of loss of heterozygosity (LOH) in tumor samples. A 250-bp fragment containing codon 72 of the human p53 gene was amplified, ThaI digested and electrophoresed. Tumor LOH is detectable both by ethidium bromide staining and autoradiography, despite 25% contamination with normal DNA. This technique provides a fast and reproducible alternative to conventional Southern blotting and has minimal sample requirements.