Figure 1 Loss of heterozygosity (LOH) analysis of head and neck squamous cell carcinoma (HNSCC) samples with chromosome 17p markers. (A) Representative autoradiographs showing LOH at different markers on chromosome 17. The markers (shown at the bottom of each panel) were amplified from paired tumour (T) and normal (N) tissues taken from selected patients (shown at the top of each panel), analysed by denaturing 6% polyacrylamide gel electrophoresis and autoradiographed. The first pair is an example of retention of both alleles. The other two pairs are examples of loss of lower and upper alleles respectively. (B) Frequency of LOH at different markers on chromosome 17 in primary HNSCC. Names of the markers and their cytogenetic positions are shown at the bottom of each histogram.