Thermal cycle takes place in which technique

Options

A. Gel electrophoresis
B. PCR -technique
C. Centrifugation
D. Southern blotting

Answer

### Step-by-Step Solution:

1. **Understanding Thermal Cycle**: The term "thermal cycle" refers to a series of temperature changes that are used in various molecular biology techniques to manipulate DNA.

2. **Identifying the Technique**: The technique that utilizes thermal cycling is the Polymerase Chain Reaction (PCR). PCR is a widely used method for amplifying specific DNA sequences.

3. **Components of PCR**: PCR involves several key components:
- **DNA Template**: The DNA that you want to amplify.
- **Primers**: Short sequences of nucleotides that provide a starting point for DNA synthesis.
- **DNA Polymerase**: An enzyme that synthesizes new DNA strands. The most commonly used is Taq polymerase, which is heat-stable.
- **Deoxynucleotides**: The building blocks of DNA.

4. **Steps of PCR**:
- **Denaturation**: The reaction mixture is heated to separate the DNA strands.
- **Annealing**: The temperature is lowered to allow primers to bind to the single-stranded DNA.
- **Extension**: The temperature is raised again to allow Taq polymerase to synthesize new DNA strands by adding deoxynucleotides.

5. **Amplification**: This cycle of denaturation, annealing, and extension is repeated multiple times (usually 25-35 cycles), resulting in the exponential amplification of the target DNA sequence.

6. **Conclusion**: The thermal cycle takes place in the PCR technique, which is essential for DNA amplification.