Which of the following is not correct for a successful PCR ?

Options

A. Thermostable DNA polymerase
B. Nanogram of DNA template
C. Primer with exposed 5-OH group only
D. Deoxyribonucleotide triphosphate

Answer

To determine which statement is not correct for a successful PCR (Polymerase Chain Reaction), we need to analyze each of the provided options based on the principles of PCR.

### Step-by-Step Solution:

1. **Understanding PCR**: PCR is a technique used to amplify a specific segment of DNA. It requires specific components to function effectively.

2. **Evaluate the Options**:
- **Option A: Thermostable DNA polymerase**: This is a requirement for PCR. The enzyme must be heat-resistant to withstand the high temperatures used during the denaturation step of PCR.
- **Option B: Nanogram of DNA template**: This is also correct. A small amount of DNA template (in nanograms) is necessary for PCR to amplify the DNA.
- **Option C: Primer with exposed 5-hydroxyl group only**: This statement is incorrect. For PCR to work, primers need to have an exposed 3-hydroxyl group, not a 5-hydroxyl group. The DNA polymerase adds nucleotides to the 3'-OH end of the primer.
- **Option D: Deoxyribonucleotide triphosphate (dNTP)**: This is a correct requirement. dNTPs are the building blocks that DNA polymerase uses to synthesize new DNA strands.

3. **Conclusion**: Based on the analysis, the incorrect statement regarding the requirements for a successful PCR is **Option C: Primer with exposed 5-hydroxyl group only**.

### Final Answer:
**Option C** is not correct for a successful PCR.

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