In RT-PCR, what is the role of reverse transcriptase?

In RT-PCR, what is the role of reverse transcriptase?

• A. To degrade RNA templates during PCR.
• B. To synthesize DNA from a DNA template.
• C. To synthesize complementary DNA from RNA.
• D. To ligate RNA fragments.

Answer: (C)

The main concept is that reverse transcriptase creates a DNA copy of an RNA template. In RT-PCR, RNA (such as mRNA or viral RNA) is used as a template for the enzyme, which builds a complementary DNA strand. This cDNA then serves as the template for the standard PCR amplification by DNA polymerase. Since PCR cannot copy RNA directly, this step is essential to allow the RNA sequence to be amplified. Reverse transcriptase does not degrade RNA, nor does it synthesize DNA from a DNA template or ligate RNA fragments.

The main concept is that reverse transcriptase creates a DNA copy of an RNA template. In RT-PCR, RNA (such as mRNA or viral RNA) is used as a template for the enzyme, which builds a complementary DNA strand. This cDNA then serves as the template for the standard PCR amplification by DNA polymerase. Since PCR cannot copy RNA directly, this step is essential to allow the RNA sequence to be amplified. Reverse transcriptase does not degrade RNA, nor does it synthesize DNA from a DNA template or ligate RNA fragments.