西亚试剂：：Plasmid DNA Isolation from Bacteria

Materials:

TENS solution:
10 mM Tris (pH to 7.5)
1 mM ethylenediaminetetraacetic acid (pH to 8.0 to dissolve)
0.1 N sodium hydroxide
0.5 % sodium dodecyl sulfate
3 M Sodium acetate, pH 5.2
Pre-chilled (at -20 degrees C) 100 % ethanol
70 % Ethanol
Distilled water
Overnight bacterial culture (LAB 5)
Supplies:

Micropipetter and tips
Vortex mixer
Microcentrifuge and tubes
Procedures:

Spin 1.5 ml of overnight bacterial culture for 30-60 seconds in a microcentrifuge. (observation: bacteria form a pellet at the bottom of the tube.)
Decant supernatant, leaving 50-100 ul in the tube.
Vortex to resuspend the bacteria pellet completely.
Add 300 ul of TENS solution.
Vortex for 5 seconds to mix. (observation: the contents of the tube should become slimy.)
Add 150 ul of the sodium acetate.
Vortex for 5 seconds to mix.
Spin for 2 minutes in a microcentrifuge. (observation: a white pellet, containing bacterial debris, is formed at the bottom of the tube.)
Transfer supernatant to a fresh tube.
Add 0.9 ml of pre-chilled 100 % ethanol.
Spin for 5 minutes in a microcentrifuge. (observation: a white pellet, containing plasmid DNA and bacterial RNA, is formed at the bottom of the tube.)
Discard supernatant and add 1 ml of 70 % ethanol.
Discard the ethanol and add another 1 ml of 70 % ethanol.
Withdraw and discard as much liquid (ethanol) as possible then air-dry the pellet.
Resuspend the pellet in 30 ul of distilled water and keep at 4 degrees C or -20 degrees C.
Results:

Plasmid DNA is now ready for estimation of DNA concentration (LAB 4) followed by restriction digest (LAB 3).
Typical yield is 2-3 u