A building block used for derivatization of carboxylic acids or activated esters with methyltetrazine moiety. The stability of Methyltetrazine-PEG4-Amine is substantially improved compared to hydrogen substituted tetrazines. The aqueous solubility of this reagent is substantially enhanced by a hydrophilic polyethylene glycol (PEG) spacer arm. This reagent is supplied as HCl salt for improved stability and easy handling.
An amine-reactive labeling reagents with enhanced reactivity and water solubility.