Introduction to a DNA Library
In humans, there are approximately 25,000-35,000 genes among the 3 billion DNA base pairs in the human genome. Genes are nothing but sequences of DNA that code for the synthesis of RNA molecules used to make proteins. In order to study a gene, a researcher needs to isolate it from all the other genes in an organism’s DNA. One method involves the construction of a DNA library. It is a collection of DNA fragments that come from one organism and are stored in another organism, often a bacterium such as E.coli.
Before we open the doors and venture inside a DNA library, it is essential to get back to basics with terms such as DNA, mRNA and cDNA.
DNA or deoxyribonucleic acid molecules, which contain ATGC base pairs, make up the chromosome. Moreover, DNA molecules consist of two specific regions: exons and introns -- the former code for proteins while the latter i.e., introns are non-coding regions of DNA that are not involved in protein production. The DNA of eukaryotic organisms contains both exons and introns. However, prokaryotes lack introns.
When DNA is transcribed, it forms mRNA (messenger RNA), which when translated codes for a particular protein.
Now, everyone is familiar with the term library. You go to a college library to search specific books and they are so arranged that it takes no time to find the one you want. In genetics, a DNA library is constructed to help scientists find specific genes.