Precipitates of purified DNA after the addition of chilled ethanol are seen as a collection of the fine threads in suspension. This process is referred as

Options

A. 1) DNA transformation
B. 2) DNA ligation
C. 3) DNA spooling
D. 4) DNA duplication

Answer

To solve the question regarding the process that describes the appearance of purified DNA as fine threads in suspension after the addition of chilled ethanol, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**: The question describes a laboratory process involving the precipitation of DNA using chilled ethanol. This is a common technique used in molecular biology to isolate DNA from a solution.

2. **Analyze the Options**: The options provided are:
- 1. DNA transformation
- 2. DNA ligation
- 3. DNA spooling
- 4. DNA duplication

3. **Evaluate Each Option**:
- **DNA Transformation**: This refers to the uptake of foreign DNA by a cell. It does not relate to the precipitation of DNA, so this option is incorrect.
- **DNA Ligation**: This is the process of joining two DNA strands together using the enzyme DNA ligase. It is not related to the precipitation of DNA, making this option incorrect as well.
- **DNA Spooling**: This is the process where DNA precipitates out of solution and can be collected as fine threads. This matches the description given in the question, making it a strong candidate for the correct answer.
- **DNA Duplication**: This refers to the process of copying DNA, which is unrelated to the precipitation of DNA. Therefore, this option is also incorrect.

4. **Identify the Correct Answer**: Based on the analysis, the correct answer is **DNA spooling** (Option 3), as it accurately describes the process of collecting precipitated DNA as fine threads in suspension.

### Final Answer:
The process referred to in the question is **DNA spooling** (Option 3).