Fluorescent labeling of biomolecules enables researchers to detect specific components of complex biological assemblies with exquisite sensitivity in applications ranging from imaging and flow cytometry, to Western blots. We offer a full spectrum of Invitrogen™ Molecular Probes™ labeling chemistries for labeling antibodies, proteins, peptides, ligands, synthetic oligonucleotides and other biomolecules for use with immunochemistry, fluorescence in situ hybridization (FISH), cell tracing, receptor labeling, and cytochemistry applications as well as probing biological structure, function and interactions. Also available are tools for conjugation of biotin and other haptens to biomolecules.

Use the Molecular Probes Labeling Chemistry Selection Tool to determine the appropriate reactive dyes for your experiments.

Labeling Chemistry Selection Tool


Find Your Labeling Product

Labeling Amines

Labeling Amines   Amine-reactive dyes are widely used to modify proteins, peptides, ligands, synthetic oligonucleotides and other biomolecules. They are most often used to prepare bioconjugates for immunochemistry, fluorescence in situ hybridization (FISH), cell tracing, receptor labeling and cytochemistry.



Labeling Thiols

Labeling Thiols   Efficiently prepare fluorescent proteins, peptides, and sulfhydryl-modified oligos for analyzing protein structure and function.



Bifunctional Crosslinking

Bifunctional Crosslinking   Bifunctional cross-linking reagents to covalently link two target groups, including amine–amine, amine–thiol, and amine–carboxylic acid.



Labeling Proteins, Peptides & Antibodies

Labeling Proteins, Peptides & Antibodies   A comprehensive selection of innovative and time-tested  antibody and protein labeling kits including our monoclonal antibody labeling kits, Invitrogen™ APEX™ antibody labeling kits and our classic protein labeling kits.



Labeling QC & Calibration

Labeling QC & Calibration   Optimize results with reference standards to calibrate instruments, compare results, determine degree of labeling, or generate standard curves.  




Research Tools


New Cell Analysis Support Center
Find tips, troubleshooting help, and resources for your cell analysis workflow.