The NucleoSpin 96 Plasmid Kits are designed for purifying up to 20 µg of high-copy plasmids from 1–5 ml E. coli overnight culture, preferably grown in LB medium. The NucleoSpin Plasmid Binding Strips/Plates contain a unique silica membrane that binds DNA in the presence of chaotropic salt. 96-well plates can be processed manually, under vacuum, or by centrifugation.
The NucleoSpin 8/96 Plasmid procedure is a modified version of the Birnboim and Doly alkaline lysis plasmid miniprep protocol. Bacterial cultures are harvested by an initial centrifugation step. After resuspension of the pelleted bacteria (Buffer A1) and alkaline cell lysis (Buffer A2), a neutralization and binding buffer (Buffer A3) containing chaotropic salts is added. The resulting bacterial crude lysates are cleared by vacuum filtration with the NucleoSpin Plasmid Filter Strips/Plate. The cleared lysates containing the plasmid DNA are collected in the NucleoSpin Plasmid Binding Strips/Plate. The chaotropic salt enables a reversible adsorption of plasmid DNA to the NucleoSpin silica membrane during the second vacuum filtration step. High purity is achieved in the final plasmid DNA preparation by complete removal of cellular contaminants, salts, detergents, and other compounds in subsequent washing steps. Highly pure plasmid DNA is eluted with Elution Buffer AE (5 mM Tris / HCl, pH 8.5) or water (pH 8.0– 8.5), and can directly be used for downstream applications.