What are the applications of cDNA library?

cDNA library is made up of a collection of cDNA fragments, each of which is a cloned copy of mRNA (messenger RNA). cDNA library is a powerful and useful tool with a wide range of applications in the field of biotechnology.

1. It allows researchers to study expression of mRNA.
2. It helps in the expression of eukaryotic genes in prokaryotes, which facilitates the transcription process of prokaryotes.
3. It is used to isolate DNA sequences that code for a particular mRNA. 
4. It is useful in reverse genetics where the additional genomic information is not required.