Genotype analyses for two SNPs in the factor VII gene by using a thermal gradient chip. Fluorescence units (y-axis) as a function of chip island temperature (x-axis) are shown for hybridization of Cy 5-labeled, denatured PCR, and solution-phase targets to chip-bound normal (N-ASO, red) or mutant (M-ASO, green) oligonucleotide probes. Genomic DNA from individuals either heterozygous (N/M, middle panels), homozygous wild type (N/N, left panels), or homozygous mutant (M/M, right panels) encompassing either the G353A (upper three panels) or C-122T (lower three panels) SNPs in the factor VII gene were amplified by PCR. Samples then were heat denatured and annealed to chips containing the five different thermally isolated islands. Chips were washed and scanned as described in Methods. Numbers in brackets refer to the ratio of intensities of annealing of labeled targets to normal (red)/mutant (green) probe spots on the array.