What are the experimental steps of dna extraction?

Using the solubility of nucleic acid in water, after breaking the tissue cells, RNA was removed with low salt solution, and the precipitate was dissolved in water, so that DNA was completely dissolved in water. After centrifugation, the supernatant was collected. Add solid sodium chloride to the supernatant and adjust it to 2.6M. Add twice the volume of 95% ethanol and stir immediately.

Washing with 66%, 80% and 95% ethanol and copper propionate respectively, and finally drying in the air to obtain DNA samples. Protein content in DNA extracted by this method is high, so it is generally not used. In order to remove protein, the method can be improved by adding SDS in the extraction process. This method is used in the relatively simple teaching of general school laboratories.

Extraction principle

1 to ensure the integrity of the primary structure of nucleic acid;

2. There should be no organic solvents and metal ions with high concentration that can inhibit enzymes in nucleic acid samples;

3. The pollution of other biological macromolecules such as protein, polysaccharide and lipid molecules should be reduced to a minimum;

4. Other nucleic acid molecules, such as RNA, should be removed as much as possible.

Refer to the above content: Baidu Encyclopedia -dna Extraction