Technique used to detect the complementary DNA is a clone is

Options

A. PCR
B. Gel electrophoresis
C. Chromatography
D. Autoradiography

Answer

To solve the question regarding the technique used to detect complementary DNA clones, we will analyze each option provided and identify the correct one.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the technique used to detect complementary DNA clones. This implies we need a method that can identify whether a specific DNA sequence is present in a clone.

2. **Analyzing the Options**:
- **PCR (Polymerase Chain Reaction)**: This technique is primarily used for amplifying DNA. While it can indicate the presence of a DNA sequence, it does not directly detect or visualize complementary DNA clones.
- **Gel Electrophoresis**: This method is used for separating DNA fragments based on size. It can show the presence of DNA but does not specifically detect complementary sequences.
- **Chromatography**: This is a separation technique used for various biomolecules but is not specifically designed for detecting DNA sequences.
- **Autoradiography**: This technique involves using radiolabeled probes that can hybridize with complementary DNA sequences. It allows for the visualization of DNA that has hybridized with a labeled probe, thus indicating the presence of complementary DNA.

3. **Conclusion**: Among the options, autoradiography is the technique that specifically detects complementary DNA clones by visualizing the hybridization of a radiolabeled probe with the target DNA.

### Final Answer:
The technique used to detect complementary DNA is **Autoradiography**.

---