While isolating DNA from bacteria, which of the following enzymes is not used ?

Options

A. A. Lysozyme
B. B. Ribonuclease
C. C. Deoxyribonuclease
D. D. Protease

Answer

To solve the question of which enzyme is not used while isolating DNA from bacteria, we can analyze the options provided:

1. **Lysozyme**: This enzyme is commonly used to break down the cell wall of bacteria, facilitating the release of DNA. Therefore, it is used in the DNA isolation process.

2. **Ribonuclease (RNase)**: This enzyme is used to degrade RNA. Since RNA is often present alongside DNA in the extraction process, RNase helps in purifying the DNA by removing RNA. Thus, it is also used in DNA isolation.

3. **Deoxyribonuclease (DNase)**: This enzyme specifically degrades DNA. Since the goal of isolating DNA is to obtain it in a pure form, DNase would not be used during this process, as it would break down the DNA we are trying to isolate.

4. **Protease**: This enzyme is used to digest proteins that may be present in the sample. It helps to purify the DNA by removing proteins, so it is also used in the isolation process.

Based on this analysis, the enzyme that is not used while isolating DNA from bacteria is **C. Deoxyribonuclease (DNase)**.

### Step-by-Step Solution:
1. Identify the purpose of each enzyme in the context of DNA isolation.
2. Analyze the role of Lysozyme in breaking down bacterial cell walls.
3. Determine the function of Ribonuclease in removing RNA from the sample.
4. Evaluate the role of Deoxyribonuclease in degrading DNA, which makes it unsuitable for isolation.
5. Understand the function of Protease in removing proteins during the purification process.
6. Conclude that the enzyme not used in isolating DNA is Deoxyribonuclease (DNase).