Asante NaTRIUM Green 1
Asante NaTRIUM Green-1 is a visible wavelength fluorescent indicator with a useful dynamic range for measuring cytosolic Na+ concentrations. Unlike SBFI, it loads readily into cells and is excited by visible light. Although ANG-1 excites maximally at 517 nm, its exceptional brightness enables excitation at the standard 488 nm settings used for the Fluo calcium indicators. Moreover, it works well for 2-photon excitation with near-infrared light. ANG-1 is also remarkable in its resistance to photobleaching and leakage.
ANG-1 has been phased out in favor of the improved performance ANG-2. ANG-2 shares the same properties of ANG-1 with a lower kd of 18 mM
Evaluation of the Sodium Sensing Dye Asante Natrium Green 2 in a Voltage-gated Sodium Channel Assay in 1536-well Format
Gregory T. O'Donnell, Kelli Solly, Carissa Quinn, Brian Squadroni, Eric Johnson, Jeffrey Hermes, and Michael Finley
Department of Exploratory Sciences and Screening
Merck Research Laboratories 140-154 Wissahickon Ave, North Wales, PA 19454, USA
Learn more about Asante Natrium Green-2.
Excitation: 488-517 nm (excitation maximum at 517 nm)
Emission: 540 nm
Kd: 85 mM
Solubility: H2O (salt form) DMSO (AM form)
Molecular Weight: 1100 g/mol
A recent article by Christophe Lamy, and Jean-Yves Chatton highlights the uses and improved performance of TEFLabs' novel sodium indicator, Asante NaTRIUM Green-1™.
Lamy CM & Chatton JY. Optical probing of sodium dynamics in neurons and astrocytes. NeuroImage 2011 (in press)
ANG-1 Emission Spectra
Screening mode (FIG. 2.1): HEK293 cells expressing TRPV1 channels were loaded with ANG-1. Capsaicin, an agonist for TRPV1 channels, which conduct Na+ and Ca2+, was used to stimulate Na+ influx. The capsaicin-evoked rise in ANG-1 fluorescence is robust. [J. Kao, Univ. of Maryland]
FIG. 2.1 ANG-1 in HEK293 cells
Flow cytometry and wide-field microscopy mode (FIG. 2.2): REF52 cells were loaded with ANG-1, and the Na+ ionophore gramicidin was applied to promote Na+ influx . in the resulting rise in intracellular Na+ concentration caused a corresponding increase in ANG-1 fluorescence. [J. Kao, Univ. of Maryland]
FIG. 2.2 ANG-1 in REF52 cells
Confocal microscope mode (FIG. 2.3): Astrocytes were loaded with ANG-1 and ouabain, a sodium pump inhibitor, was used to block Na+ extrusion from the cell. The second frame shows the consequent increase in ANG-1 fluorescence from a baseline after only three minutes of treatment with ouabain. (Courtesy JY Chatton, Univ of Lausanne)
Baseline Ouabain(3 min.)
ANG-1 (AM) cell loading procedure for the experiments of Figures 2.1 and 2.2. (This procedure should not be treated as a general loading protocol for ANG-1. Please refer to Chapter 1 for general loading guidelines.)
(i) 1-5 µM of ANG-1 (AM) is an average concentration.
(ii) The sample is prepared with ~75 ppm Pluronic F-127 for dispersing the dye into the incubator buffer.
(iii) For these experiments, the buffer consisted of HCO3- DMEM with 10% fetal bovine serum (FBS) and cells were kept under 5% CO2 atmosphere.
(iv) Loading time varied from 45 minutes to 70 minutes.
(v) The experiments were conducted in HBSS.
[J. Kao of Univ. of Maryland Medical School]