Fluorescent reagents of many types continue to be developed to stain or chemically label proteins, nucleic acids and other biomolecules. When specific antibodies or other purified biomolecules are chemically labeled with fluorescent dyes, they become fluorescent probes for detection of target antigens or interaction partners in applications such as cell imaging, high-content analysis, flow cytometry, western blotting and ELISA.

Our comprehensive portfolio of fluorescent reagents now includes products from two highly respected legacy product lines: Invitrogen™ Molecular Probes™ (known for Alexa Fluor™ Dyes and the Molecular Probes™ Handbook) and Thermo Scientific™ Pierce™ (known for DyLight™ Fluors and crosslinking chemistry) fluorescent reagents.

Whether your needs are for already-labeled, ready-to-use fluorescent secondary antibodies or for specific reagents and kits to chemically label and prepare your own probes, we almost certainly offer the product you are looking for.

Featured fluorescent protein labeling reagent categories

Microscale Protein Labeling Kits

Microscale Protein Labeling Kits conveniently label small amounts (20–100 μg) of purified protein or antibodies with a bright, photostable Alexa Fluor® dye or biotin-XX.

Large Scale Protein Labeling Kits

Molecular Probes® Protein Labeling Kits provide a nearly effortless way to label 1 mg of IgG with a fluorescent dye (including Alexa Fluor® dyes) or biotin.


Molecular Probes® labeling reagents enable researchers to create their own labeled biomolecule for use many different applications.

DyLight® Fluors Technology & Product Guide

Thermo Scientific™ DyLight ™ Fluorescent Dyes are a complete family of high-intensity, photostable fluorescent tags for labeling antibodies and other molecular probes.

Fluorescent Secondary Antibodies

Fluorescent-dye conjugated secondary antibodies provide a much needed tool for identifying proteins in many applications including fluorescent cell imaging, western blotting, immunohistochemistry and more.

Biotin Binding Protein Conjugates

Streptavidin-based amplification techniques are widely used in flow cytometry, fluorescent imaging, western blotting, and microplate-based detection for increased signal output and greater sensitivity.

Protein quantitation immunoassays
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