FAQs

Phycobiliproteins (PBPs) stored in PBS with ammonium sulfate maintain excellent long-term stability. However, the ammonium sulfate form requires additional purification steps, such as dialysis or sulfate precipitation, to remove the ammonium sulfate before creating tandem dyes or antibody conjugations. We offer PBPs stored in PBS with ammonium sulfate for your convenience.

Yes, our R-PE & APC Labeling Kits are SH-reactive, designed to link efficiently with free sulfhydryl (-SH) groups on antibodies. The maleimide (-NH2) groups in our crosslinked R-PE and APC form a stable covalent bond with these sulfhydryl groups, requiring no additional activation. You can also use these kits to label other molecules with free sulfhydryl groups.

After conjugation, the reaction mixture primarily contains the R-PE-antibody conjugate, with minimal amounts of free R-PE and antibody. While free R-PE typically does not affect assay results, we recommend purification for labeling up to 1 mg of antibody. Feel free to contact us for further technical guidance.

Yes, our labeling kits are designed to be scalable. You can divide a large pack into smaller vials to suit your experimental needs.

The molecular weight of purified R-PE is 240 kDa, and for purified APC is 105 kDa. They are both perfect for detecting cell surface antigens to further conduct cell screening and cell imaging. With high molecular weight, PE and APC won't penetrate into the cell sample even if cell membrane ruptured, which greatly lower the risk of false-positive reaction. It should be noted that the relatively high molecular weight of R-PE may preclude its use in procedures requiring good penetration into cells and tissues. It is predominantly intended for surface labeling of cells for flow cytometry.