The polymerase chain reaction is a method of A) performing gel electrophoresis. B) DNA amplification. C) making cDNA. D) making an RNA probe

Break Down the Problem

1. Identify what the polymerase chain reaction (PCR) primarily accomplishes.
2. Understand the context in which PCR is used in molecular biology.

Relevant Concepts

• Polymerase Chain Reaction (PCR): A laboratory technique used to amplify small segments of DNA.

Analysis and Detail

• Option A: Performing gel electrophoresis is a technique for separating nucleic acids or proteins but is not what PCR does.
• Option B: DNA amplification is indeed the primary purpose of PCR, as it replicates a specific DNA segment exponentially.
• Option C: Making cDNA involves reverse transcription from RNA, which is a different process.
• Option D: Making an RNA probe is related to labeling RNA, not the DNA amplification function of PCR.

Verify and Summarize

The primary role of the polymerase chain reaction is to amplify DNA, thereby producing millions of copies from a small initial sample.

Final Answer

B) DNA amplification.