Now a third labeling option is available, which promises to alleviate the shortcomings of other methods. Madison, Wis.-based Promega Corp.'s FluoroTect™ GreenLys in vitro translation labeling system is a BODIPY®-FL-labeled lysine residue coupled to tRNALys. BODIPY is a fluorophore, so proteins prepared in vitro may be immediately visualized following electrophoresis, using a laser-based fluorescent imaging system (such as the FluorImager® SI, FluorImager 595, or Typhoon™ 8600, from Molecular Dynamics, or with the FMBIO® II from Hitachi Instruments). The BODIPY label has an absorption maximum of 502 nm, and an emission maximum of 510 nm.
To use this system, scientists need only add 1-2 µl of the FluoroTect reagent to a standard IVT reaction. Since it is supplied as a charged tRNA, the labeled tRNALys is immediately available to the ribosomes, without the need for in vitro charging. Because of the ability to detect labeled proteins "in-gel," researchers can avoid traditional ...
