Maleimide-Activated R Phycoerythrin (ab270023) is designed to facilitate the conjugation of R-Phycoerythrin to proteins, peptides and ligands that contain sulfhydryl (-SH) groups. The reactive maleimide group that has been added to R-Phycoerythrin allows conjugation to be performed very efficiently at physiological pH.

This product is manufactured by Expedeon, an Abcam company. It was previously called Maleimide-R Phycoerythrin (2mg)SKU: 403-0002. Expedeon product code 403-0002 is the same as the 2 mg size of this product.

The buffer in which the thiolated molecule is dissolved should be in the pH range 6.5-7.5. Phosphate buffered saline pH 7.2 is commonly employed. EDTA (1-10 mM) may help to prevent metal catalyzed oxidation of thiols.

Please see the below table for recommended buffer conditions and components:

Molecules that do not contain –SH groups can be chemically modified to introduce the required thiol functionality.

Abcam offers a thiolation kit (ab270020) compatible with this product.

In the case of antibodies, disulfide (S-S) bridges may also be cleaved to release free thiols. Any reducing reagent (e. g. dithiothreitol and β-mercaptoethanol) used to produce free thiols should be removed before proceeding with the conjugation.