1. Pour the supernatant containing the DNA (leaving behind the precipitated protein pellet) into a 1.5 ml microfuge tube containing 300 l 100% isopropanol (2-propanol).
2. Cap the tube and mix the sample by inverting gently 50 times.
3. Centrifuge at 13,00016,000 x g for 1 min; the DNA will be visible as a small white pellet.
4. Pour off supernatant and drain tube briefly on clean absorbent paper. Add 300 l 70% ethanol and invert capped tube several times to wash the DNA pellet.
5. Centrifuge at 13,00016,000 x g for 1 min. Carefully pour off the ethanol. Pellet may be loose, so pour slowly and watch pellet to ensure it stays in the tube.
6. Invert and drain the tube on clean absorbent paper and allow to air-dry for 15 min.
1. Add 50 l DNA hydration solution (50 l will give a concentration of 100 g/ml if the total yield is 5 g DNA).
2. Allow DNA to rehydrate overnight at room temperature. Alternatively, heat at 65C for 1 hr. Tap tube periodically to aid in dispersing the DNA. Store DNA at 28C.
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