Promega has recently introduced the SiStrike U6 hairpin cloning system — hMGFP. The system consists of an expression vector with an internal fluorescent marker for monitoring delivery of shRNA-expressing constructs.

The marker, said Promega, is an improved synthetic version of the green fluorescent protein, hMGFP, originally cloned from Montastrea cavernosa. The synthetic gene expresses a 26kDa protein, which shows improved fluorescence and reduced cytotoxicity when compared to the native gene.