What is the First Step in Constructing a Metagenomic Library

Question

What is the first step in constructing a metagenomic library from RNA?
A) The RNA must be converted to cDNA.
B) The RNA must be amplified through PCR, producing many RNA copies.
C) The RNA must be screened to identify the genes of interest.
D) The RNA must be inserted into plasmid vectors.

Accepted Answer

The first step in constructing a metagenomic library from RNA is to convert the RNA to cDNA. This is accomplished through the use of reverse transcriptase, which synthesizes a single-stranded DNA copy (cDNA) of the RNA template. This cDNA can then be amplified and inserted into plasmid vectors to construct the library. Therefore, choice A is the correct answer. PCR amplification and screening of genes of interest would come later in the library construction process.