Biotin-PEG4-amido-methyltetrazine is an aqueous soluble PEGylation reagent containing a biotin and a methyltetrazine group. Methyl group improves the stability and hydrophilic PEG spacer increases water-solubility. Methyltetrazine enable fast click reaction with TCO (trans-cycloctene). The spacer arm helps to minimize steric hindrance involved with the binding to avidin molecules. Reagent grade, for research purpose. Please contact us for GMP-grade inquiries.