Cluster analysis of tag array hybridization results for 44 individuals at SNP marker (A) ANPex3.33 and (B) SELP.25. The logarithm of total fluorescence intensity [(PM−MM)_fluorescein + (PM−MM)_{phycoerythrin}] for each of the 44 hybridizations is plotted against the calculated relative allele fraction value P. The three distinct clusters observed correspond to the genotypes T/T, T/C, and C/C for marker ANPex3.33, and T/T, T/G, and G/G for marker SELP.25.