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Invitrogen™ PBFI, Tetraammonium Salt, cell impermeant

PBFI is potassium-sensitive molecule used measure intracellular K+ fluxes in animal cells and in plant cells and vacuoles

Manufacturer:  Invitrogen™ P1265MP


Catalog No. P1265MP

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  • Although selectivity of PBFI for K+ is less than that of calcium indicators such as fura-2, it is sufficient for detection of physiological concentrations of K+ in presence of other monovalent cations
  • Spectral response of PBFI upon ion binding permit excitation ratio measurements, and this indicator can be used with same optical filters and equipment used for fura-2
  • Label (Ex/Em): PBFI (approximately 340,380/500nm)
  • Lyophilized product may be dissolved in distilled water or aqueous buffer for use
  • Product is typically loaded into cells by diffusion from patch pipet for correlated fluorescence imaging and electrophysiological recording
  • Kd of PBFI for K+ is strongly dependent on whether Na+ is present, with value of 5.1mm in absence of Na+ and 44mm in solutions with combined Na+ and K+ concentration of 135mm (which approximates physiological ionic strength)
  • Although PBFI is only 1.5-fold more selective for K+ than for Na+, this selectivity is often sufficient because intracellular K+ concentrations are normally about 10 times higher than Na+ concentrations

Cell Analysis, Cell Metabolism, Cell Viability, Proliferation and Function, Ionic Homeostasis and Signaling, Sodium and Potassium Detection

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Shipping Condition: Room temperature



Fluorescence Microscope
Potassium Indicator
Room Temperature
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For Research Use Only. Not for use in diagnostic procedures.