From RNA to PCR template — Bulk RNA can be analyzed by PCR after reverse transcription into which nucleic acid form?

Introduction / Context:Standard PCR requires DNA as a template. To analyze RNA transcripts, the RNA must first be converted into complementary DNA (cDNA) by reverse transcription, creating a DNA template suitable for amplification. This combined method is called reverse-transcription PCR (RT-PCR) or, in quantitative formats, RT-qPCR.

Given Data / Assumptions:

• Input is RNA (e.g., total RNA or mRNA).
• Reverse transcriptase synthesizes a DNA strand complementary to the RNA template.
• Subsequent PCR uses DNA polymerase on this cDNA.

Concept / Approach:Reverse transcription yields cDNA, a DNA copy of the RNA sequence. This cDNA is then amplified using PCR primers complementary to sequences of interest. tRNA and rRNA are specific RNA classes, not DNA forms; “m DNA” is not a recognized term. Therefore, the correct product enabling PCR from RNA is cDNA.

Step-by-Step Solution:

Verification / Alternative check:Successful RT-PCR shows amplicons even when no genomic DNA is present; minus-RT controls confirm the amplification derives from cDNA, not contaminating DNA.

Why Other Options Are Wrong:

• tRNA / rRNA: RNA species, not DNA; cannot serve as DNA templates for standard PCR.
• m DNA: not a standard term in molecular biology.

Common Pitfalls:Forgetting DNase treatment of RNA to remove genomic DNA, which can otherwise confound RT-PCR results.

Final Answer:c DNA