Biotinylation reagents and kits

The biotin-avidin interaction is commonly exploited to detect and/or purify proteins because of the high specificity that these two molecules have for each other. Biotinylation is the process of attaching biotin to proteins and other macromolecules. Biotinylation reagents are available for targeting specific functional groups or residues, including primary amines, sulfhydryls, carboxyls and carbohydrates. Photoreactive biotin compounds that react nonspecifically upon exposure to ultraviolet (UV) light are also available and expand the scope of the molecules that may be biotinylated. 

The variety of biotinylation reagents with different functional group specificities is extremely useful, allowing one to choose a reagent that does not inactivate the target macromolecule.

  • Primary amine groups (–NH2) are found on lysine side chains and at the amino terminus of each polypeptide chain.
  • Sulfhydryl groups (–SH) can be generated by reducing disulfide bonds in the hinge region.
  • Carbohydrate residues containing cis-diols can be oxidized to create active aldehydes (–CHO).

Biotin labeling reagents and kits for labeling proteins and antibodies

Labeling reagents and kits to specifically biotinylate antibodies and other proteins or peptides with biotin labels at primary amines (ε-lysine and N-terminus), the most abundant reactive group on the surface of proteins, for streptavidin detection.

Maleimide, iodoacetyl and cleavable pyridyldithiol activated biotin labeling reagents and kits to specifically biotinylate antibodies and other proteins or peptides at sulfhydryl groups, such as reduced free thiols on cysteine residues.

Hydrazide-activated labeling reagents to biotinylate polyclonal antibodies and other glycoproteins with biotin labels at oxidized sugar and carbohydrate groups for streptavidin detection and purification.

Amine-modified biotin labels to specifically biotinylate peptides (C-terminus), carboxyl-coated surfaces and other carboxylic acid groups using the carbodiimide crosslinker, EDC (or EDAC). 

Azido, psoralen and other photo-reactive (UV-activated) biotin labeling compounds to biotinylate proteins, nucleic acids or organic molecules for use as molecular probes with streptavidin conjugates. 

Desthiobiotin reagents for chemically labeling proteins and other molecules with a form of biotin that provides soft-release elution from streptavidin for purification applications. 

Simple and accurate HABA dye assay and fluorescent detection kits to measure the amount of biotin attached to proteins or other biomolecules to determine the molar ratio of free biotin to the biotin labeled molecule.