Why is the yield of pMAL DNA from plasmid preps so low?
The pMAL plasmids are pBR322-copy number, but for unknown reasons the yield from plasmid preps is often lower than what can be obtainined from pBR322. However, modification of the standard alkaline lysis protocol can increase the yield: increasing the volume of the buffers by 1.5 x doubles the yield of plasmid (i.e., for a 500 ml culture, resuspend the cell pellet in 15 ml instead of the standard 10 ml, and increase the denaturing and neutralizing buffer amounts proportionately).
