Learn how to use this product The chemically competent E. coli TOP10 cells are provided as 20 separate one-shot reactions, ready for heat shock transformation with vector DNA and its subsequent propagation for cloning and transfection purposes. The transformed cells can be selected using blue/white screening. The genotype of Competent E. coli TOP10 cells is as follows: F- mcrA (mrr-hsdRMS-mcrBC) 80lacZ M15 lacX74 recA1 ara 139 (ara-leu)7697 galU galK rpsL (StrR) endA1 nupG.