Find the wrong pair.

Options

A. Separation of DNA - Gel electrophoresis
B. Precipitation of DNA - Chilled Ethanol
C. Staining of DNA - Ethydium bromide
D. Mutiple copies of DNA - Selectable marker

Answer

To find the wrong pair from the given options, we will analyze each option step by step:

1. **Separation of DNA in Gel Electrophoresis**:
- In gel electrophoresis, DNA fragments are separated based on their size. The negatively charged DNA moves towards the positive electrode when an electric current is applied. This option is correct.

2. **Specification of DNA by Ethanol**:
- Ethanol is commonly used to precipitate DNA from a solution. When DNA is mixed with ethanol, it becomes less soluble and can be separated from the solution. This option is also correct.

3. **Staining of DNA by Ethidium Bromide**:
- Ethidium bromide is a fluorescent dye that intercalates between DNA bases. When exposed to UV light, it fluoresces and allows visualization of DNA bands. This option is correct as well.

4. **Multiple Copies of DNA Selected by Marker**:
- The term "multiple copies of DNA selected by marker" is misleading. Selectable markers are used to identify transformed cells that have taken up foreign DNA, but they do not directly relate to the selection of multiple copies of DNA. This option is incorrect.

Based on the analysis, the wrong pair is the fourth option regarding "Multiple copies of DNA selected by Marker."

### Final Answer:
The wrong pair is: **Multiple copies of DNA selected by Marker.**