optiCall uses both within and across sample intensity information to accurately ascertain genotypes from across the minor allele frequency spectrum.
optiCall works by first taking a random subset of intensity measures, both within and across samples. The subset is used to define regions of high probability for the three genotype classes. Genotypes are then called on a per SNP basis, with all samples overlaid onto the probability regions, which are incorporated as a data-derived.prior during clustering. In this way common variants are seen as three clouds in a per SNP view, and rare variants are called based on the intensity region in which they fall.