Thermo Scientific EZ-Link Sulfo-NHS-LC-LC-Biotin enables simple and efficient biotin labeling of antibodies, proteins, and any other primary amine–containing macromolecules. Specific labeling of cell surface proteins is another common application for these uniquely water-soluble and membrane impermeable reagents.

Thermo Scientific No-Weigh products are specialty reagents provided in a pre-aliquoted format. The pre-weighed packaging prevents the loss of reagent reactivity and contamination over time by eliminating the repetitive opening and closing of the vial. The format enables use of a fresh vial of reagent each time, eliminating the hassle of weighing small amounts of reagents and reducing concerns over reagent stability.

Features of EZ-Link Sulfo-NHS-LC-LC-Biotin:

• Protein labeling—biotinylate antibodies to facilitate immobilization, purification or detection using streptavidin resins or probes
• Cell surface labeling—biotinylates only surface proteins of whole cells because the negatively charged reagent does not permeate cell membranes
• Amine-reactive—reacts with primary amines (-NH2), such as the side-chain of lysines (K) or the amino-termini of polypeptides
• Soluble—charged sulfo-NHS group increases reagent water solubility compared to ordinary NHS-ester compounds
• Irreversible—forms permanent amide bonds; spacer arm cannot be cleaved
• Doubly long —spacer arm (total length added to target) is 22.4 angstroms; this extended arm helps to minimize steric hindrance for biotin binding

Sulfo-NHS-LC-LC-Biotin is the longest of three very similar EZ-Link Reagents that are water-soluble, non-cleavable, and enable simple and efficient biotinylation of antibodies, proteins and any other primary amine-containing macromolecules in solution. Specific labeling of cell surface proteins is another common application for these uniquely water-soluble and membrane impermeable reagents. Differing only in their spacer arm lengths, the three Sulfo-NHS-ester reagents offer the possibility of optimizing labeling and detection experiments where steric hindrance of biotin binding is an important factor.

We manufacture biotin reagents to ensure the highest possible overall product integrity, consistency, and performance for the intended research applications.

N-Hydroxysulfosuccinimide (NHS) esters of biotin are the most popular type of biotinylation reagent. NHS-activated biotins react efficiently with primary amino groups (-NH2) in alkaline buffers to form stable amide bonds. Proteins (e.g., antibodies) typically have several primary amines that are available as targets for labeling, including the side chain of lysine (K) residues and the N-terminus of each polypeptide.

Varieties of biotin NHS-ester reagents differ in length, solubility, cell permeability and cleavability. Non-sulfonated NHS-biotins are cell permeable but must be dissolved in organic solvent such as DMSO or DMF. Sulfo-NHS biotins (and those with pegylated spacers) are directly water soluble but not membrane permeable. Varieties containing disulfide bonds can be cleaved using reducing agents, enabling the biotin group to be disconnected from the labeled protein.