NiCo21(DE3) is designed for protein expression from vectors which encode the phage T7 promoter. However, NiCo21(DE3) is also compatible with any promoter that is recognized by the E.coli RNA polymerase such as Plac, Ptac, Ptrc, ParaBAD, PrhaBAD and PT5-lac.
The pUC19 vector is supplied as a control to test transformation efficiency. pUC19 encodes a lac promoter but due to the high-copy number we do not recommend pUC19 for protein expression.