EZ-Link™ Micro Sulfo-NHS-SS-Biotinylation Kit - FAQs

View additional product information for EZ-Link™ Micro Sulfo-NHS-SS-Biotinylation Kit - FAQs (21945)

11 product FAQs found

Is there a cleavable analog of Sulfo-NHS-LC-Biotin?

Yes, we offer Sulfo-NHS-SS-Biotin (Cat. Nos. 21331, 21328). It has a disulfide bond in the spacer arm that can be cleaved with DTT or other reducing agents, thereby releasing the biotin tag from the previously labeled protein. This product is also available in kit format (Cat. Nos. 21945, 21445).

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

Which EZ-Link Micro Biotinylation Kit is best for my application?

All four Micro Biotinylation Kits will label proteins for use in many applications. Consider the following guidelines for choosing among the kits:

• Choose the Sulfo-NHS-Biotinylation Kit (Cat. No. 21925) when it is important to minimize the molecular mass contributed by the label.
• Choose the Sulfo-NHS-SS-Biotinylation Kit (Cat. No. 21945) only when the downstream application require cleaving the biotin tag with a reducing agent.
• Choose the NHS-PEG4-Biotinylation Kit (Cat. No. 21955) to maximize protein solubility and prevent protein aggregation during storage.
• Choose the Sulfo-NHS-LC-Biotinylation Kit (Cat. No. 21935) for routine purposes when a feature of one of the other reagents is not required. The longer spacer arm offers the possibility of optimizing detection experiments where steric hindrance of biotin binding is an important factor.

Find additional tips, troubleshooting help, and resources within our Protein Assays and Analysis Support Center.

How long does it take to biotinylate a protein using the EZ-Link Micro Biotinylation kits?

The entire procedure can be completed in less than 3 hours.

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What types of proteins can be labeled with the EZ-Link Micro Biotinylation kits?

Any molecule containing a primary amine can be labeled. Any protein that has been labeled using the standard biotinylation kits, including antibodies and peptides, also can be labeled with the micro kits.

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Are the biotinylation reagents in the EZ-Link Micro Biotinylation Kits cleavable?

Only the sulfo-NHS-SS-Biotin is cleavable because it has a disulfide bond in its spacer arm, enabling labeled proteins to be cleaved from the biotin group by treatment with reducing agents.

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What are the reaction chemistries of the reagents in the EZ-Link Micro Biotinylation Kits?

The reagents in the Micro kits are amine reactive. NHS esters react with a-amines at the N-termini and the epsilon-amines of lysine side chains at pH 7-9 to form stable amide bonds and the release of NHS.

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Are the included biotinylation reagents in the EZ-Link Micro Biotinylation Kits water soluble?

Yes, the four Micro kits contain water-soluble biotinylation reagents; three kits contain sulfo-NHS reagents and one kit contains a polyethylene glycol (PEG) reagent. The sulfo-NHS ester imparts water solubility and is the reaction leaving group. The hydrophilic PEG spacer arm imparts water solubility that is maintained after conjugation.

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How many EZ-Link Micro Biotinylation kits are available?

There are four Micro Biotinylation Kits as shown below:

• EZ-Link Micro Sulfo-NHS-Biotinylation Kit, Cat. No. 21925
• EZ-Link Micro Sulfo-NHS-LC-Biotinylation Kit, Cat. No. 21935
• EZ-Link Micro Sulfo-NHS-SS- Biotinylation Kit, Cat. No. 21945
• EZ-Link Micro NHS-PEG4-Biotinylation Kit, Cat. No. 21955


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Can I use the HABA assay to verify conjugation after using the EZ-Link Micro Biotinylation Kits?

The HABA assay requires a large volume of biotinylated sample. Using the HABA assay with the Micro Biotinylation kits consumes too much of the sample. An alternative verification method is to perform a dot blot of the biotinylated protein using streptavidin-HRP or other labeled avidin product.

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How do the EZ-Link Micro Biotinylation Kits differ from the standard biotinylation kits?

The standard biotinylation kits contain components for labeling 1-10 mg of protein, and the Micro Biotinylation Kits are structured for labeling 50-200 µg of protein in 200-700 mL. The Micro kits contain the biotinylation reagents in small, individual packages and do not include components to perform the HABA assay.

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Can you provide the shelf-life for EZ-Link Micro Sulfo-NHS-SS-Biotinylation Kit?

EZ-Link Micro Sulfo-NHS-SS-Biotinylation Kit 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. 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.

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