Extraction of DNA from Goat Liver

Principle
DNA can be isolated from cells and tissues by high salt or phenol extraction. Here, chromatin and proteins are dissociated by treatment with SDS. The proteins are denatured by phenyl chloroform treatment. It becomes insoluble and can be prepared by the following chemicals.

Materials

• Ethanol
• Saline
• EDTA
• pH-8.0 (0.9% NaCl and 0.01 M EDTA)
• 10% SDS
• 80% phenol
• 95% ethanol

Procedure

1. 2.5 gm of liver tissue was homogenized in 25 mL of saline EDTA and transferred to a 250-mL conical flask.
2. To this, 2.5 mL of 10% SDS and 2.5 mL of 80% phenol was added and shaken well for 10 minutes.
3. The entire mixture was centrifuged at 10000 rpm for 10 minutes. The aqueous layer was separated out.
4. To the remaining material, (interphase + phenol phase), equal volume of chloroform, isoamyl alcohol (24 : 1) was added and shaken for 25 minutes.
5. It was again centrifuged at 10000 rpm for 10 minutes.
6. The aqueous phase was collected.
7. To the aqueous phase, equal volume of 80% phenol was added and again centrifuged at 10000 rpm for 10 minutes.
8. To the aqueous phase obtained, 95% ice cold ethanol was added and then the flask was shaken gently.
9. The DNA are precipitated as a white mass.

Result
By the addition of ice-cold ethanol, DNA strands were obtained as a white mass or turbidity.