Which of the following has popularised the PCR (polymerase chain reactions)?

Options

A. a) Easy availability of DNA template
B. b) Availability of synthetic primers
C. c) Availability of cheap deoxyribonucleotides
D. d) Availability of 'thermostable' DNA polymerase

Answer

**Step-by-Step Solution:**

1. **Understanding PCR**: PCR, or polymerase chain reaction, is a technique used to amplify a specific segment of DNA, producing millions of copies of that segment. This process is crucial for various applications in molecular biology, including cloning, gene expression analysis, and genetic testing.

2. **Identifying the Options**: The question presents four options regarding what has popularized PCR. We need to analyze each option to determine which one is correct.

3. **Analyzing Option A - Easy Availability of DNA Template**: While having a DNA template is necessary for PCR, the easy availability of the template itself does not significantly contribute to the popularity of the PCR technique. Therefore, this option is incorrect.

4. **Analyzing Option B - Availability of Synthetic Primers**: Synthetic primers are essential for PCR as they initiate the DNA synthesis process. However, they can be quite expensive, which limits their accessibility. Thus, this option does not contribute to the popularity of PCR, making it incorrect.

5. **Analyzing Option C - Availability of Cheap Deoxyribonucleotides**: Deoxyribonucleotides (dNTPs) are the building blocks of DNA. The availability of these nucleotides at a low cost has indeed made PCR more accessible and popular in various research and clinical settings. Therefore, this option is correct.

6. **Analyzing Option D - Availability of Thermostable DNA Polymerase**: Thermostable DNA polymerases, such as Taq polymerase, are crucial for PCR as they can withstand the high temperatures used in the process. However, while they are important, their availability does not directly contribute to the widespread popularity of PCR compared to the cost of dNTPs. Hence, this option is incorrect.

7. **Conclusion**: After analyzing all options, the correct answer is Option C: the availability of cheap deoxyribonucleotides has popularized PCR.

**Final Answer**: Option C - Availability of cheap deoxyribonucleotides.

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