• Protein labeling—biotin antibodies to facilitate immobilization, purification or detection using streptavidin resins or probes• Antibody labeling—biotin antibodies to facilitate immobilization, purification or detection using streptavidin resins or probes• Cell surface labeling—biotin 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 lysine side-chains, 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• Medium length—spacer arm (total length added to target) is 22.4 angstroms; provides excellent balance between adequate length (minimal steric hindrance for biotin binding) and modest mass

Sulfo-NHS-LC-Biotin is one of three very similar EZLink 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. Sulfo-NHS-LC-Biotin is offered in several package sizes and as complete protein labeling kits.