Qiagen QIAprep Spin Miniprep Kit ( 27104 or 27106 ) with a microcentrifuge
Resuspend pelleted bacterial cells in 250μl Buffer P1 and transfer to a micro - centrifuge tube .
Add 250 μl Buffer P2 and mix thoroughly by inverting the tube 4–6 times .
Add 350 μl Buffer N3 and mix immediately and thoroughly by inverting the tube 4–6 times .
Centrifuge for 10 min at 13,000 rpm ( ~ 17,900 x g ) in a table - top microcentrifuge .
Apply the supernatants from step 4 to the QIAprep spin column by decanting or pipetting .
Centrifuge for 30–60 s .
Discard the flow - through .
Wash the QIAprep spin column by adding 0.5 ml Buffer PB and centrifuging for 30–60 s .
Discard the flow - through .
Wash QIAprep spin column by adding 0.75 ml Buffer PE and centrifuging for 30–60 s .
Discard the flow - through , and centrifuge at full speed for an additional 1 min to remove residual wash buffer .
Place the QIAprep column in a clean 1.5 ml microcentrifuge tube .
Centrifuge for 1 min .
Let stand 1 minute .
Add 50 μl buffer EB or water to the center of each QIAprep spin column .
Centrifuge 1 - 5mL bacterial overnight culture at > 6800g for 3 minutes at room temperature .
