Yellow-green fluorescent, potassium indicator, membrane permeable. Higher potassium affinity than IPG-1 and IPG-2, with improved selectivity for potassium over sodium. 

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Frequently bought together



525 nm 


545 nm 


7 mM




Synonyms: Asante Potassium Green, Ion Potassium Green, APG, IPG, APG-4, IPG-4
Product code: 10 x 50ug: 3021F/ 500ug: 3021C

product description

ION Potassium Green – 4 (IPG-4) is a yellow-green fluorescent, potassium (K⁺) indicator with Ex/Em: 525 nm/545 nm and a high-selectivity for potassium over other monovalent cations. IPG-4 has the highest affinity (Kd = 7 mM) among IPG analogues – IPG-2 (Kd = 18 mM) and IPG-1 (Kd = 50 mM), and is useful for measuring changes in intracellular or extracellular potassium concentrations.

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IPG-4, a potassium indicator, fluorescence spectra

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GIRK channel (Kir3.1/3.2) activator dose response curve comparison with data acquired using IPG-4 AM on a plate reader and microscope. Inset shows a dose response curve generated using thallium flux.
Fluorescence data of IPG-4 potassium indicator response to potassium.

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Image analysis of IPG-4 assay used to identify activators of a GIRK potassium channel.
Fluorescence profiles and images of cells loaded with IPG-4 in the presence or absence of probenecid demonstrating IPG-4 is not a Pgp substrate, and can be used to conduct probenecid-free potassium channel assays.

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