Question

Both RT-PCR and construction of a cDNA library measure expression of a gene(s). What are the enzyme(s) that are used in both techniques?

Option 1: DNA polymerase.
Option 2: RNA polymerase.
Option 3: Reverse transcriptase.
Option 4: Ligase.

Answer 1

Reverse transcriptase and DNA polymerase are the enzymes used in both RT-PCR and the construction of a cDNA library; reverse transcriptase synthesizes cDNA from mRNA, and DNA polymerase amplifies the cDNA obtained.

Step-by-step explanation:

The enzymes that are used in both RT-PCR and the construction of a cDNA library are reverse transcriptase and DNA polymerase. Reverse transcriptase is used to convert mRNA into cDNA by adding DNA nucleotides to the RNA template. This process is known as reverse transcription. After cDNA is synthesized, DNA polymerase is then used to amplify the cDNA through the PCR process, making multiple copies for further analysis.

In the context of RT-PCR, reverse transcriptase is vital for detecting gene expression by converting RNA transcript back into DNA, while the construction of a cDNA library also begins with the use of reverse transcriptase to create a representative cDNA population from the expressed mRNAs. DNA polymerase is then involved in synthesizing the second DNA strand and amplifying the cDNA fragments.