NovaBlue competent cells are for routine molecular cloning applications. NovaBlue is a K-12 strain derivative that offers high transformation efficiency, facilitates plasmid stability, and allows blue/white screening with appropriate plasmids.
http:// www.emdmillipore.com/US/en/product/NovaBlue-Singles-Competent-Cells-Novagen,EMD_BIO-70181?bd=1