Key definition: libraries

A DNA library is a set of sequences or clones

Types of libraries:

 

Genomic: each clone contains a small (typically 1-10kb) insert derived from the cleavage of genomic DNA

EST (expressed sequence tag): each clone contains a fragment of a gene product, obtained by transcribing mRNA in vitro. Most of these relate to a specific tissue (eg root or leaf)‏

BAC (bacterial artificial chromosome): a genomic library, where each clone contains a large piece (~100kb) of genomic DNA, derived from the cleavage of genomic DNA either with a rare-cutting restriction enzyme such as NotI, or by incomplete digestion with a common restriction enzyme such as BamHI