Genomic Library

A genomic Library is collection of plasmid clones or phage lyates conianing recombinant DNA molecules so that the sum total of DNA inserts in this collection, ideallym repsresents the entire genome of the concerned organism. However, inspite of all the cre taken in the production of genomic libraries, certian DNA gragments should be expected to be under or over represented or even missing. The possible reasons for this may be that certain fragments code for a toxic product, or might replicate slowly or might have been altered by recombinational events during clonign in addition endonuclease cleavage sites are often not recongnised equally well. Certain DNA fragments may therefore never appear in partial digests by a restriction endonuclease used for the constriuction of genomic libraries.