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.
  • Simple—ready to use in 2 hours, requiring approximately 30 minutes actual hands-on time
  • Reliable—protein conjugates with stable attachment of fluorescent labels for subsequent use in fluorescence-based imaging or flow cytometry
  • Convenient—easiest method to label larger amounts of IgG antibody

Protein Labeling Kit selection guide

Label
Ex/Em
Flow cytometry
Imaging
Cat. No.
Alexa Fluor® 350
346/442
Alexa Fluor® 488
495/519
Alexa Fluor® 532
532/553
Alexa Fluor® 546
556/573
Alexa Fluor® 555
555/565
Alexa Fluor® 568
578/603
Alexa Fluor® 594
590/617
Alexa Fluor® 633
621/639
Alexa Fluor® 647
650/665
Alexa Fluor® 660
663/690
Alexa Fluor® 680
679/702
Fluorescein
494/518
Oregon Green® 488
496/524
Pacific Blue™ dye
410/455
Pacific Orange™ dye
400/551
Texas Red® dye
595/615
Biotin
NA
Ex/Em = Fluorescence excitation and emission maxima, in nm.
Find more information about Alexa Fluor® dyes and other fluorophores in the Fluorophore Selection Guide

How Protein Labeling Kits work

The Protein Labeling Kits utilize an amine-reactive fluorophore or hapten to covalently attach the label to the IgG antibody. Once formed, the covalent bond between the label and the protein is extremely stable—you are using the same chemistry we use to prepare our own primary and secondary conjugates. 

Simply add ~1 mg of purified IgG (in ~500 μL and free of amine-containing buffers such as Tris) to one of the vials containing a premeasured quantity of amine-reactive dye and a magnetic stir bar. Purification is accomplished on a gravity-feed size exclusion column supplied with the kit (Figure 1). The entire labeling and purification procedure can be completed in as little as 2 hours; everything needed to perform three conjugations is provided.

Protein Labeling Kits
Figure 1. Molecular Probes® Protein Labeling Kits are the simplest way
to label 1 mg of IgG antibodies.

Need to label other antibody amounts?

IgG amount Attachment of label Products
<1–20 µg Site-specific Zenon® Antibody Labeling Kits
<100 µg Site-specific SiteClick™ Antibody Labeling Kits
10–20 µg Conventional covalent APEX® Antibody Labeling Kits
20–100 µg Conventional covalent Microscale Protein Labeling Kits
100 µg Conventional covalent Antibody Labeling Kits
1 mg Conventional covalent Protein Labeling Kits
0.5–3 mg Conventional covalent SAIVI™ Rapid Antibody Labeling Kits
Custom fluorescent antibody and protein labeling service
Alexa Fluor® Labeling Kits