Why you chose mRNA rather than genomic DNA for making a DNA library?

Answer 1

Complementary DNA (cDNA) is a doublestranded DNA version of RNA . Messenger RNA is a more useful predictor of a polypeptide sequence than DNA, because the introns have been spliced out. Scientists use cDNA rather than mRNA itself because RNAs are less stable than DNA.

Answer 2

as wikipedia says,

"a cDNA library lacks the non-coding and regulatory elements found in genomic DNA. Genomic DNA libraries provide much more detailed information about the organism, but are much more resource-intensive to generate and maintain."

Answer 3

Genomic DNA contains non-coding sections called introns that take up too much space and interfere with gene cloning and genetic engineering experiments. The point of having a DNA library is to have a set of reference genes which can be used depending on the requirements of the research.

During the process of transcription, an mRNA copy is generated from a DNA template and in this process, the non-coding sequences (or introns) are removed. Thus, only the region of the gene which codes for a functional protein is maintained in the mRNA sequence. This is the reason why is is more beneficial to isolate these mRNA's and create a library of sequences.

Ideally, these mRNA sequences are converted to cDNA through the reverse transcriptase enzyme and placed in a cDNA library. These cDNA libraries are more applicable in molecular Biology.