CompactPrep Plasmid Maxi Kit (25)

From QIAGEN, the CompactPrep Plasmid Maxi Kit is designed for fast, large-scale plasmid DNA purification from bacterial cultures. The kit includes CompactPrep Maxi Columns, extender tubes, reagents, buffers and LyseBlue reagent, and can be stored at room temperature (15–25°C) for up to 2 years if not otherwise stated on the label.

For high-copy plasmids the maximum recommended Luria Bertani (LB) culture volume is 100 ml, and for low-copy plasmids it is 250 ml. Bacterial cells are harvested by centrifugation at 6000 x g for 15 min at 4°C, then the pellet is resuspended in 5 ml Buffer P1, lysed with 5 ml Buffer P2 for 3 min at room temperature, and precipitated with 5 ml Buffer S3. After clearing the lysate by centrifugation at ≥20,000 x g for 30 min at 4°C, 5 ml Buffer BB is added before loading the sample onto the column. Bound DNA is washed with 0.7 ml Buffer PE and eluted with 200 µl of Buffer EB (10 mM Tris·Cl, pH 8.5) or water.

Optional use of LyseBlue reagent, added to Buffer P1 at a ratio of 1:1000, gives a visual indication of complete lysis, and RNase A solution should be added to Buffer P1 to a final concentration of 100 µg/ml. The expected yield from the Maxi format is up to 750 µg of plasmid DNA. A Quick-Start Protocol is available from the manufacturer.