A genomic library is a set of clones that together represents the entire genome of a given organism. The number of clones that constitute a genomic library depends on (1) the size of the genome in question and (2) the insert size tolerated by the particular cloning vector system. For most practical purposes, the tissue source of the genomic DNA is unimportant because each cell of the body contains virtually identical DNA (with some exceptions).
Applications of genomic libraries include:
* Determining the complete genome sequence of a given organism (see genome project)
* Serving as a source of genomic sequence for generation of transgenic animals through genetic engineering
* Study of the function of regulatory sequences in vitro
* Study of genetic mutations in cancer tissues