VPB 321: Animal Biotechnology (2+1)

DNA LIBRARIES

• Vectors are used to compile a library of DNA fragments that have been isolated from the genomes of a variety of organisms.
• This collection of fragments can then be used to isolate specific genes and other DNA sequences of interest.
• DNA fragments are generated by cutting the DNA with a specific restriction endonuclease.
• These fragments are ligated into vector molecules, and the collection of recombinant molecules is transferred into host cells, one molecule in each cell.
• The total number of all DNA molecules makes up the library.
• This library is searched, that is screened, with a molecular probe that specifically identifies the target DNA.
• Once prepared the library can be perpetuated indefinitely in the host cells and is readily retrieved whenever a new probe is available to seek out a particular fragment.
• Two main types of libraries can be used to isolate specific DNAs:
•  genomic and
• cDNA libraries.