and gstp1 c were determined by the combination of gstp1 113 and gstp1 104 genotypes as follows gstp1 a 113c 104a gstp1 b 113c 104g and gstp1 c 113t 104g gene dosage for gstm1 and gstt1 was determined by comparing the area under the curve auc of their products to the auc of co amplified homozygous controls cdk2 and gstm3 respectively auc ratios are near linear but may require optimization with the first set of patient samples specifically the genotype results are shown for five separate cell line derived dna samples each line represents four different combined pcr reactions from a single dna sample source the genotype corresponding to each sample is shown at the end of each line the gene dosage for gstm1 was determined by examining the ratios of the peak area under the curve of gstm1 vs cdk2 the gene dosage for gstt1 was determined by examining the ratios of the peak area under the curve of gstt1 vs gstm3 ratios greater than 1 0 were interpreted to represent genotypes gstm1 non null gstt1 null independent experiments verifying gstm1 and gstt1 gene dosage by an independent long range pcr assay though the data in fig1 was gathered using dna.