FAQs

Differences between phycobiliproteins stored in PBS only and in PBS with ammonium sulfate?


Home Algae offers phycobiliproteins stored in PBS and PBS with ammonium sulfate suspension.

Although both exhibit good long-term stability, the form with ammonium sulfate require more purification processes, such as dialysis, sulfate precipitation or gel filtration chromatography, to fully remove the ammonium sulfate impurities prior to tandem dye or antibody conjugation.




Is the conjugation reaction linking the R-PE/APC to free sulfhydryl groups on the antibody?


Home Algae's R-PE & APC Labeling Kit are SH-reactive labeling kits. Activated R-PE and APC have maleimide (-NH2) groups that easily react with sulfhydryl (-SH) groups of target antibody without the need for additional activation. The maleinide group of R-PE/APC and sulfhydryl group on the antibody form a covalent bond during conjugation. You can also use activated R-PE & APC to label other molecules that have free sulfhydryl groups.




What are the molecular weight of R-PE and APC?


The molecular weight of R-PE is 240 kDa, and 105 kDa for APC. They are both perfect for screening of cell surface and cell sorting. With high molecular weight, PE and APC won't penetrate into the cell sample when cell membrane ruptured, which lower the risk of false-positive reaction.




Do I need to remove the free R-PE from the R-PE-antibody conjugate?


After the conjugation procudures, reaction mixture should contain mostly the R-PE-antibody conjugate, with small amounts of unconjugated R-PE and antibody. Unconjugated R-PE should not interfere with the assay result. However, purification is suggested for labeling up to 1 mg of antibody. Please contact us for more technical advice.




Can I purchase large pack of labeling kit and seperate them into small vials on my own for several reactions?


All pack sizes of our labeling kits are for one reaction. Please discuss the amount and desired packaging with us for the latest special offers.





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