DNA library or the gene library is the collection of DNA sequences from different organisms. These DNA sequences have been extracted, purified, sequenced and associated with a vector so as to use them for the purpose of analysis, comparative detection etc.
Depending on the source of DNA, the DNA library can be of the following two types:
A) Genomic Library: In these libraries, the whole genome of an organism is used. The information of the whole genome is made available. These can be further of two types:
1. Nuclear Genomic Library: Nuclear DNA is purified and stored.
2. Organelle Genomic Library: Organellar DNA (from mitochondria or chloroplast) Is purified and stored
B) cDNA Library: When the mRNAs from a cell are extracted and DNA is made from mRNA through reverse transcription, such a DNA is called cDNA (complementary DNA). In cDNA library, only the cDNA (that are functional in a cell) are made and stored. In other words, cDNA library has a collection of mRNAs of an organism, in the form of cDNA.
Advantages of DNA libraries:
Disadvantages of DNA libraries: