Question

Regarding DNA extraction:

1) Describe the purpose of each of the following steps or reagents used in DNA isolation (in detail):

- Using fresh vs. dried specimens

- Grinding or tearing tissue

- Lysis solution

- TE buffer

Answer 1

Question

DNA extraction is performed in order to extract DNA from the give plant or animal cell. The purpose of following step in the DNA extraction step include:

I. Using fresh vs dried specimen

The fresh specimen are good to isolate the DNA from the cells. In animal cells, DNA extraction is mainly done at the fresh samples. The isolation of DNA in fresh sample maximize the chance of success. But in case of plant and fungal cells, dried specimen are used because they get maximum success when sample is dried as it contain intact DNA in their cells.

II. Grinding or tearing tissue

The grinding of the tissue is done in order to disrupt the cell wall of the plants and fungi. In animal cells, the purpose of the grinding is to break connective tissue. The other purpose of the grinding is to produce small clump of cells that further help in the lysis of DNA extraction.

III. Lysis solution

The purpose of the lysis is to break the nuclear membrane as well as the plasma membrane. The lysis of the cell membrane open the cells so that various components of the cells are able to break. This is done by breaking the bonds present in the plasma membrane of the cell.

IV. TE buffer

Tris EDTA (TE buffer) in the DNA extraction is use to dissove the DNA and help it to get protect DNA from degradation. As, the DNA contain some proteins and other substance attach with it, therefore, it is very essential to purify the DNA from the other cellular debris.