The Precision Plus Protein™ Dual Xtra Standard provides 12 reference bands, from 2 kD to 250 kD. Researchers can use Dual Xtra’s bands to monitor the electrophoresis process and transfer of proteins from gel to membrane during Western blotting as well as for estimating molecular weight of protein samples. The 12 dual-color bands, in pink and blue, facilitate straightforward analysis of orientation of proteins in the gel and on the blot. At 2 kD, the smallest pink reference band clearly stands out from the dye front. The bands are verified by mass spec for consistent migration from lot to lot and more reliable molecular weight estimation. The dyes used are naturally fluorescent, so they can also be used for fluorescent multiplexing.