A molecular lab introduces droplet digital PCR (ddPCR) for hepatitis C RNA quantification. What key advantage does ddPCR have over standard real-time RT-PCR?

• A ddPCR provides absolute quantification independent of a standard curve with high precision at very low viral loads ✓
• B ddPCR requires a standard calibration curve and is affected by PCR efficiency variability
• C ddPCR is faster than real-time PCR for routine clinical use
• D ddPCR cannot quantify RNA; it works only for DNA targets

Explanation

Digital PCR partitions the sample into thousands of droplets and performs end-point PCR in each; by counting positive and negative droplets using Poisson statistics, it gives absolute copy number quantification without relying on a standard curve, making it especially accurate at very low viral loads (e.g., end-of-treatment HCV RNA, minimal residual disease). Standard real-time RT-PCR requires a calibration curve and is susceptible to efficiency variation. ddPCR can amplify RNA targets using reverse transcription (RT-ddPCR). It is slower and more expensive than RT-PCR.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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