Chilled ethyl alcohol is used during DNA technology for

Options

A. Precipitation of histones
B. Precipitation of DNA
C. Removal of enzymes
D. Precipitation of cell fragments .

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Chilled Ethyl Alcohol in DNA Technology:**
Chilled ethyl alcohol (ethanol) is commonly used in DNA extraction and purification processes. The primary purpose of using chilled ethanol is to precipitate DNA from a solution.

2. **Mechanism of DNA Precipitation:**
When chilled ethanol is added to a solution containing DNA, it causes the DNA to become insoluble. This is because ethanol reduces the solubility of nucleic acids in the solution, leading to the formation of a precipitate.

3. **Temperature's Effect on Enzymes:**
The use of chilled conditions is crucial because it helps maintain the stability of enzymes involved in the DNA extraction process. Lower temperatures prevent the denaturation of these enzymes, allowing them to function effectively during the extraction.

4. **Exclusion of Other Options:**
- **Precipitation of Histones:** This is incorrect as histones are typically precipitated using chloroform, not ethanol.
- **Removal of Enzymes:** This is also incorrect because enzymes are necessary for the DNA technology processes and are not removed.
- **Precipitation of Cell Fragments:** This option is incorrect as well, since chilled ethanol specifically precipitates nucleic acids, not cell fragments.

5. **Conclusion:**
Therefore, the correct answer to the question is that chilled ethyl alcohol is used during DNA technology for the **precipitation of DNA**.

**Final Answer:** Precipitation of DNA.

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