Using an automated mass spectrometric genotyping platform, we have completed more than ten whole-genome SNP scans on phenotypically stratified population pools. The pools are usually constructed to represent one ethnicity, one gender, and one phenotype, classified as strictly as possible. From 28,000 to 91,000 different SNPs are used for each study, and the pools typically contain DNA from 300 different individuals. Significant correlations between SNP allele and phenotype are first reproduced in the pools, then replicated on individual DNA samples (deconvolution of the pools), and then where possible replicated in completely independent populations.