what is c-DNA ?
cDNA refers to the complementary DNA synthesized by the enzyme reverse transcriptase and DNA Polymerase from the mature eukaryotic messenger RNA. This mature messenger Eukaryotic mRNA does not contain any introns, it has only axons. The DNA, thus formed, is complementary to mRNA hence known as cDNA.
In genetics, complementary DNA (cDNA) is DNA synthesized from a messenger RNA (mRNA) template in a reaction catalysed by the enzymes reverse transcriptase and DNA polymerase. cDNA is often used to clone eukaryotic genes in prokaryotes. When scientists want to express a specific protein in a cell that does not normally express that protein (i.e., heterologous expression), they will transfer the cDNA that codes for the protein to the recipient cell. cDNA is also produced naturally by retroviruses (such as HIV-1, HIV-2, Simian Immunodeficiency Virus, etc.) and then integrated into the host's genome where it creates a provirus.