Animal Biotechnology

cDNA LIBRARY

• A cDNA library is a collection of cloned cDNA (complementary DNA) fragments inserted into a collection of host cells, which together constitute some portion of the transcripts of the organism.
• cDNA is produced from fully transcribed mRNA found in the nucleus and therefore contains only the expressed genes of an organism.
• Similarly, tissue specific cDNA libraries can be produced.
• In eukaryotic cells the mature mRNA is already spliced, hence the cDNA produced lacks introns and can be readily expressed in a bacterial cell.
• While information in cDNA libraries is a powerful and useful tool since gene products are easily identified, the libraries lack information about enhancers, introns, and other regulatory elements found in a genomic DNA library.