What is the primary purpose of a no-template (negative) control in a PCR experiment?

What is the primary purpose of a no-template (negative) control in a PCR experiment?

• A. It quantifies template DNA.
• B. It detects contamination or non-specific amplification.
• C. It reduces reaction time.
• D. It enhances amplification efficiency.

Answer: (B)

In PCR, you want to verify that any amplification you see comes from the intended template DNA, not from accidental sources. A no-template control includes all reaction components except DNA template. If you detect a product in this control, it signals contamination or non-specific amplification (such as primer-dimers), meaning reagents or the environment contributed DNA or artifacts. Detecting such contamination helps you trust the results from your actual samples. Conversely, if the negative control shows no amplification, you can be more confident that the observed products in test reactions come from the template you added. This control does not quantify template DNA, speed up the reaction, or boost amplification efficiency; its role is to reveal potential contamination or unintended amplification.

In PCR, you want to verify that any amplification you see comes from the intended template DNA, not from accidental sources. A no-template control includes all reaction components except DNA template. If you detect a product in this control, it signals contamination or non-specific amplification (such as primer-dimers), meaning reagents or the environment contributed DNA or artifacts. Detecting such contamination helps you trust the results from your actual samples. Conversely, if the negative control shows no amplification, you can be more confident that the observed products in test reactions come from the template you added. This control does not quantify template DNA, speed up the reaction, or boost amplification efficiency; its role is to reveal potential contamination or unintended amplification.