During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out

Options

A. DNA
B. Histones
C. Polysaccharides
D. RNA

Explanation

**Step-by-Step Solution:**

1. **Understanding Recombinant DNA Technology**:
- Recombinant DNA technology involves the manipulation of DNA to create new genetic combinations. This process includes several steps such as isolation, purification, and analysis of DNA.

2. **Role of Ethanol in DNA Purification**:
- During the purification process, one of the key steps is the addition of chilled ethanol. Ethanol is used to precipitate nucleic acids from a solution.

3. **Identifying What Precipitates**:
- When chilled ethanol is added to a solution containing DNA, the DNA molecules become less soluble and precipitate out of the solution. This is due to the reduction in solubility of DNA in the presence of alcohol.

4. **Analyzing the Options**:
- The options provided are:
- A) DNA
- B) Histones
- C) Polysaccharides
- D) RNA
- Among these, DNA is the primary molecule that precipitates out when chilled ethanol is added.

5. **Conclusion**:
- Therefore, the correct answer to the question is option A) DNA, as it is the molecule that precipitates out during the purification process in recombinant DNA technology when chilled ethanol is added.