Accessing genetic variation: Genotyping single nucleotide polymorphisms

Understanding the relationship between genetic variation and biological fun ction on a genomic scale is expected to provide fundamental new insights in to the biology, evolution and pathophysiology of humans and other species. The hope that single nucleotide polymorphisms (SNPs) will allow genes that underlie complex disease to be identified, together with progress in identi fying large sets of SNPs, are the driving forces behind intense efforts to establish the technology for large-scale analysis of SNPs. New genotyping m ethods that are high throughput, accurate and cheap are urgently needed for gaining full access to the abundant genetic variation of organisms.