Protonex(TM) Green 500 PEG12 maleimide

Protonex(TM) Green 500 PEG12 maleimide is a thiol-reactive, pH-sensitive fluorophore specifically designed for developing pH-responsive bioconjugates to investigate processes such as antibody internalization, endocytosis, and phagocytosis in live cells. The incorporation of a polyethylene glycol (PEG12) spacer arm significantly enhances the aqueous solubility of the dye, thereby reducing the potential for bioconjugate aggregation without compromising its biological functionality. As the pH shifts from basic to acidic, Protonex(TM) Green 500 PEG12 exhibits increased fluorescence, which aligns with the acidification of intracellular vesicles. The increase in fluorescence as the pH transitions from neutral to acidic obviates the need for extensive washing steps due to its lack of fluorescence in typical extracellular environments. Protonex(TM) Green 500 PEG12 maleimide is particularly effective in monitoring acidic cellular compartments, such as phagosomes, endosomes, and lysosomes, where it exhibits significantly enhanced fluorescence, providing precise detection of these acidic sites. This characteristic facilitates the specific detection of cellular acidic compartments with reduced signal variability and improved accuracy for applications in imaging, flow cytometry, and high-content screening (HCS). The maleimide functionality allows for specific conjugation to free sulfhydryl groups from reduced cysteines in proteins or peptides, oligonucleotide thiophosphates, or small molecular ligands. Such bioconjugates are crucial for targeted detection and analysis of cellular processes like phagocytosis and endocytosis, and support comprehensive multiplexed analyses of cellular functions, enabling detailed investigations into cellular dynamics.