Maleimide Activated R-Phycoerythrin Protocol (403-0002):
Introduction
Maleimide-activated R-Phycoerythrin is designed to facilitate the conjugation of RPhycoerythrin to proteins, peptides and ligands that contain sulfhydryl (-SH) groups. The reactive maleimide group that has been added to the R-Phycoerythrin allows conjugation reactions to be performed very efficiently at physiological pH.
Storage of Maleimide-activated R-Phycoerythrin
Maleimide-activated R-Phycoerythrin is shipped at ambient temperature as a lyophilized powder containing stabilizers and should be stored at -20oC. Shelf life is >1 year.
Protocol
1. Allow the vial of maleimide-activated R-Phycoerythrin to warm to room temperature.
2. Remove the crimp seal and reconstitute the lyophilized powder by adding a buffered solution of the thiol-containing molecule. Gently agitate the vial to ensure thorough dissolution.
Note: 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 catalysed oxidation of thiols.
3. Incubate for 3-4 hours (or overnight) at room temperature and then store at 4C.
