TOP10 E. coli are provided at a transformation efficiency of 1 x 10e⁹ cfu/?g supercoiled DNA and are ideal for high-efficiency cloning and plasmid propagation. They allow stable replication of high-copy number plasmids. The genotype of TOP10 cells is similar to the DH10B?strain, and offers the following features:
 
-hsdR for efficient transformation of unmethylated DNA from PCR amplifications
-mcrA for efficient transformation of methylated DNA from genomic preparations
-lacZΔM15 for blue/white color screening of recombinant clones
-endA1 for cleaner preparations of DNA and better results in downstream applications due to the elimination of non-specific digestion by Endonuclease I
-recA1 for reduced occurrence of non-specific recombination in cloned DNA