APN-Amine is a bifunctional crosslinker for thiol-to-carboxyl coupling. The coupling can be performed with high selectivity in biological medium using mild reaction conditions. Amine residue readily reacts with activated carboxylic acids (e.g. NHS-esters) in basic conditions to produce stable amide bonds. APN residue can be used for coupling with free thiols (e.g. labeling of free cysteins in proteins). Standard protein labeling procedure (cysteine labeling).
Dissolve the protein in the appropriate buffer* with pH 6.5-9.0 (e.g. PBS) at 1-10 mg/mL concentration.
Apply the appropriate amount of the stock solution of the reagent (1-5 molar eq. per free cysteine residue).
Incubate at room temperature for 2 hours.
If necessary, purify the protein conjugate using SEC or ultrafiltration.