But for now, the rush is to identify and compile SNPs. Several prominent companies, including Celera Genomics, Genset SA, and Incyte Pharmaceuticals, are creating proprietary SNP databases with the intention of charging pharmaceutical and other companies for access to the collections. SNPs in dbSNP over the next 3 years. These blocks are mixed and matched by the process of recombination, as shown in Figure 1 . In theory, if you had one marker within every one of these blocks, you would have a tag for every piece of the human genome.
Recombination produces new genotypes.
But analyzing microsatellites can be difficult because the repeated sequences can cause misalignments during amplification or hybridization. Perhaps more importantly, SNPs are much more prevalent. This density should provide a more detailed map of the genome and allow researchers to locate regions of interest more precisely, the same way that having short streets instead of long ones helps pinpoint a particular house. Researchers want to know not only which genes contribute but, ultimately, which polymorphisms. Genetic studies of these diseases are quite difficult due to the relative infrequency of the current markers, but many researchers say having a good SNP map would make such experiments more feasible.