Multiple accession numbers and names exist for a particular gene in GenBank and other databases, which is due in part to submission by multiple investigators. Until common anotation exists for each gene, a search based on nucleotide sequence must be conducted on this website in order to determine whether a primer set exists for a particular gene. This may be done by either using the "Find" command in your web browser to search for the particular gene name/accession number or by using the NCBI's BLAST program (http://www.ncbi.nlm.nih.gov/BLAST/) to compare a gene sequence to the individual primer/probe sequences located in this database. For the latter, select from the list below the organism in which you are interested, use your "Select All" and "Copy" key to transfer the entire nucleotide sequence into the "Blast two sequences" program on the NCBI's website, and enter the sequence or accession number for the gene which you would like to compare. If a positive match is obained, then use the "Find" command on your web browser to locate the nucleotide sequence on this web site, click on the sequence and you will be linked to the specific primer/probe set.