mRuby and mRuby derivatives are bright monomeric red fluorescent proteins derived from Entacmaea quadricolar. They show exceptional resistance to denaturation at pH extremes.
Unlabeled variants and several modifications of sdAbs like biotin, fluorophore or DBCO conjugation are available.
In FluoTag®-X2 two fluorophore molecules are site-specifically coupled to each FluoTag molecule. Therefore, the reagent simultaneously targets two fluorophores to the protein of interest, which ensures up to two-fold („2X“)-brighter signals. Owing to the small size of the FluoTags, the distance between the target epitope and each fluorophore is ~ 3 nm.
In comparison to detection systems using conventional antibodies, FluoTag-X can thus improve the localization accuracy by 10-15 nm. Both features - superior brightness and precise fluorophore placement - render the FluoTag-X products excellent tools for all microscopy techniques.