BS3 Crosslinker

BS3 Crosslinker is a membrane-impermeable amine-reactive crosslinker. BS3 Crosslinker covalently links adjacent lysine residues in protein complexes, forms non-cleavable amide bonds with primary amines in buffers at pH 7-9, and stabilizes EGF family receptor dimers. BS3 Crosslinker is widely used in protein chemistry, protein interaction studies, cross-linking mass spectrometry (XL-MS), and cell surface protein analysis^[1][2][3]. In Vitro:Guidelines (The following is our recommended protocol, which serves only as a guideline and should be modified according to your specific needs).
1. Dissolve 10 mg BS3 Crosslinker in 350 µL of 25 mM sodium phosphate buffer (pH 7.4) to prepare a 50 mM solution.
Note: Do not use amine-containing buffers for the coupling reaction.
2. Add the BS3 Crosslinker solution to the protein sample at a 20-fold excess ratio (crosslinker:protein = 20:1), such that the final concentration of the crosslinker ranges from 0.5 to 5 mM.
3. Incubate the sample at room temperature for 45 minutes to 1 hour. If the reaction must be performed on ice, appropriately extend the incubation time.
4. Add 25 mM to 60 mM Tris solution to quench unreacted BS3 Crosslinker, and incubate at room temperature for 10-15 minutes.
5. Desalt the sample to remove unreacted BS3 Crosslinker (e.g., using methods such as gel filtration, dialysis, etc.).


BS3 Crosslinker (0.25-5.0 mM; 30 min) exhibits extremely low immobilization efficiency for recombinant Protein G and mouse monoclonal anti-horseradish peroxidase IgG1 antibody in 96-well polystyrene microtiter plates, and a higher concentration of BS3 further reduces the signal^[1].
BS3 Crosslinker (0.75 mM; 2 h) effectively stabilizes and detects EGF-induced EGFR homodimers and EGFR-HER2 heterodimers in BT474 breast cancer cells^[3].