Biological research often requires the use of molecular labels that are covalently attached to a protein of interest in order to facilitate the detection or purification of a labeled protein and its binding partners. Labeling strategies result in the covalent attachment of different molecules, including biotin, reporter enzymes, fluorophores, and radioactive isotopes to the target protein or nucleotide sequences. While multiple types of labels are available, their varied uses are preferable for specific applications. Therefore, the type of label and the labeling strategy used must be considered carefully and tailored for each application.

We offer various labeling reagents and kits to label an antibody or other protein to make a fluorescent probe, enzyme conjugate, biotinylated binding reagent, or iodine-labeled tracer for detecting proteins in tissues, cells, and biochemical assays.

Featured protein labeling categories

Biotinylation reagents and kits to chemically tag and label antibodies, proteins, and peptides at particular amino acid functional groups to create labeled antibodies or other biotinylated probes for streptavidin affinity binding, purification, and detection.

Activated fluorescent dyes and kits for labeling antibody or protein functional groups with FITC, fluorescein, rhodamine, or Alexa Fluor® and DyLight™ dyes to create molecular probes for fluorescence imaging

We offer a number of antibody and protein labeling kits for the direct attachment of the broad range of intensely fluorescent dyes and labels including Alexa Fluor® dyes, DyLight® Fluor dyes, Qdot® labels, R-phycoerythrin (R-PE) and APC tandem dyes, and biotin

Bioorthogonal azide-modified amino acids, sugars, and other compounds for metabolic incorporation into proteins and macromolecules to enable labeling and chemoselective conjugate with alkyne or phosphine reagents via Staudinger ligation chemistry.

Horseradish peroxidase (HRP), alkaline phosphatase (AP), and other substrate enzymes in purified, activated, and kit formats are available for conjugation to proteins and for the preparation of antibody conjugates for immunoassays.

Iodination uses tyrosine addition compounds and tyrosyl activation vessels (replacing chloramine T oxidation reagents) to efficiently label proteins and other molecules with radioactive iodine,  for use as tracers and probes.

Try premium grade reagents, offering high-quality formulations for selected chemical modification reagents which have been specially characterized for applications where product integrity and risk minimization are critical.