Merck, 806595-50MG, APN-Azide

Application
APN-Azide is a bifunctional crosslinker for thiol-to-alkyne coupling. This coupling can be performed with high selectivity in biological medium using mild reaction conditions.

Standard protein labeling procedure (cysteine labeling)
1. Dissolve the protein in the appropriate buffer* with pH 6.5-9.0 (e.g. PBS) at 1-10 mg/mL concentration.
2. Apply the appropriate amount of the stock solution of the reagent (1-5 molar eq. per free cysteine residue).
3. Incubate at room temperature for 2 hours.
4. If necessary, purify the protein-azide conjugate using size exclusion chromatography or ultrafiltration.
5. The conjugate can be readily coupled with alkyne-containing using standard click-chemistry protocols.
*Note: avoid thiol-containing buffers.