Our Protein Labeling Kits provide a nearly effortless way to label 1 mg of IgG antibody with a fluorescent dye or hapten.

  • 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 Products

Label    Ex/Em† Cat. no.
Emission Color*
Flow Cytometry Imaging  
Alexa Fluor® 350 346/442 A10170             ● Order
Alexa Fluor® 488 495/519 A10235              ●           ● Order
Alexa Fluor® 532 532/553 A10236             ● Order
Alexa Fluor® 546 556/573 A10237             ● Order
Alexa Fluor® 555 555/565 A20174             ● Order
Alexa Fluor® 568 578/603 A10238             ● Order
Alexa Fluor® 594 590/617 A10239             ● Order
Alexa Fluor® 633 621/639 A20170              ●           ● Order
Alexa Fluor® 647 650/665 A20173              ●           ● Order
Alexa Fluor® 660 663/690 A20171              ●           ● Order
Alexa Fluor® 680 679/702 A20172             ● Order
Fluorescein 494/518 F10240              ●           ● Order
Oregon Green® 488 496/524 O10241              ●           ● Order
Pacific Blue™ dye 410/455 P30012              ●           ● Order
Pacific Orange™ dye 400/551 P30016              ●   Order
Texas Red® dye 595/615 T10244             ● Order
Biotin n/a D20655              ●           ● Order
* Gray represents fluorescence emission that is beyond the limit of human vision. † Ex/Em = Fluorescence excitation and emission maxima in nm.  

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 and 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 and 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.

Each Protein Labeling Kit includes:
Material Amount
Reactive dye 3 vials
Sodium bicarbonate 84 mg
Purification resin ~25 mL
10X Elution buffer ~25 mL
Purification column 3
Column funnel 3
Foam column holder 3
Disposable pipet 3
Collection tube, 4 ml 3

Product Information Sheet

Need to Label Other Antibody Amounts?

Zenon® Kits

< 1-20 µg
Microscale Kits

< 1-20 µg
Antibody Labeling kits

< 1-20 µg


Protein Labeling Kits

< 1-20 µg



< 1-20 µg


APEX™ Antibody Labeling kits

10-20 µg

Learn More about APEX™ Antibody Labeling Kits