EZ-Link™ Sulfo-NHS-LC-Biotin, 100 mg - FAQs

No. NHS esters hydrolyze very quickly. The container must be brought to room temperature (RT) prior to opening, then the amount of biotinylation reagent weighed, dissolved and used immediately.

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Yes. Because this molecule dissolves readily in polar solutions and is itself charged by the sodium sulfoxide group on the succinimidyl ring, it cannot permeate the cell wall or membrane of an intact cell. As long as the cell is intact, only the primary amines on the surface will be biotinylated.

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Tris is a primary amine, which will directly compete with protein primary amines for reaction with the NHS-ester activated biotin reagent. However, once a protein is labeled and desalted, Tris buffer can be used for storage or assay buffers, as appropriate for the protein and application.

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The molar excess to use depends on the concentration of the ligand to be biotinylated. Although the literature contains references that use between 2-50 molar excess of biotin, we recommend the following: 10-fold molar excess for 10 mg/mL solution of protein; 25-fold molar excess for 2 mg/mL solution of protein.

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No, the EZ-Link Sulfo-NHS-LC-Biotin, No-Weigh Format (Cat. No. A39257) should not be dissolved in water for storage. We recommended storing EZ-Link Sulfo-NHS-LC-Biotin, No-Weigh Format at -20 degrees C with desiccant as it is very moisture sensitive. Furthermore, to avoid moisture condensation onto the product, equilibrate vial to room temperature before opening.

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EZ-Link Sulfo-NHS-LC-Biotin is covered under our general 1-year warranty and is guaranteed to be fully functional for 12 months from the date of shipment, if stored as recommended (-20 degrees C). Please see section 8.1 of our Terms & Conditions of Sale (https://www.thermofisher.com/content/dam/LifeTech/Documents/PDFs/Terms-and-Conditions-of-Sale.pdf) for more details.

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Yes, EZ-Link Sulfo-NHS-LC-Biotin is routinely shipped at room temperature. This product is stable at ambient temperatures for short periods of time.

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EZ-Link Sulfo-NHS-LC-Biotin has a spacer arm length of 22.4 Angstroms while EZ-Link Sulfo-NHS-LC-LC-Biotin has a spacer arm length of 30.5 Angstroms.

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Sometimes. The biotin has to insert 9 angstrom into the pocket of avidin, streptavidin or NeutrAvidin to bind. If steric hindrance may be a problem, using a biotinylation reagent with a longer spacer arm (Sulfo-NHS-LC Biotin or Sulfo-NHS-LC-LC Biotin) may result in greater purification or deteciton.

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The sodium sulfonate group lends water solubility to the reagent.
Note: The actual biotin moiety that is added is identical between NHS and Sulfo-NHS biotins that vary only in the addition of the sodium sulfonate on the leaving group. Researchers preferring a more water soluble biotin be added to their molecule should consider a PEGylated version of biotin.

Find additional tips, troubleshooting help, and resources within our Protein Purification and Isolation Support Center.