Restriction endonucleases cleave different DNA substrates with varying efficiency. Restriction enzymes were tested on their ability to cleave various plasmids (pBR322, pUC19 and pLITMUS) under standard reaction conditions. Single sites were tested on each of these plasmids, depending on availability, and average values were taken when there was more than one data point available.
** BspMI and NmeAIII require 2 copies of its recognition sequence for cleavage to occur. Thus, the single BspMI site in pBR322 and pUC19 as well as the single NmeAIII site in pUC19 are resistant to cleavage. A 100-fold overdigestion with BspMI cuts less than half the DNA present, while a 10-fold overdigestion with NmeAIII cuts less than half the DNA present. Other plasmids may also be resistant to BspMI and NmeAIII cleavage.