The Isolation of cDNAs by Hybridization of YACs to cDNA Libraries

The isolation of genes from large candidate regions is one of the major problems for the molecular biologist. With the advent of yeast artificial chromosomes (YACs), the problem of cloning these regions is now largely solved; however, screening these large genomic regions for expressed sequences is still a very time-consuming task. The scale of this task will become even greater as the emphasis shifts to the identification of the genes involved in polygenic disorders. There are a number of methods for identifying expressed sequences, all of which have their merits and difficulties. It is likely that more than one method will be necessary to isolate all the genes coded for in a genomic region.