snarf-九游会ag

5-(and-6)-carboxy snarf-1, acetoxymethyl ester, acetate

description

the cell-permeant ph indicator, carboxy snarf-1, acetoxymethyl ester, acetate (cas #126208-13-7) has a pka of ~7.5 after de-esterification, thus is useful for measuring ph changes between ph 7 and ph 8. carboxy-snarf-1 exhibits a significant ph-dependent emission shift from yellow-orange to deep red fluorescence under acidic and basic conditions, respectively. this ph dependence allows the ratio of the fluorescence intensities from the dye at two emission wavelengths – typically 580 nm and 640 nm – to be used for quantitative determinations of ph. store at -20℃ in the dark.

chemical structures                fluorescence spectra

loading cells with snarf am acetate esters

    optimal loading conditions for each cell type and experiment should be determined by the researcher. the literature cites a wide range of loading conditions, from 1 to 20 µm snarf am acetate incubated with cells for from 10 to 60 minutes. dmso stock solutions are typically diluted at least 1:1000 into loading buffer to reduce the exposure of cells to dmso, and the loading buffer should be se rum-free because serum often contains esterase activity. the non ionic detergent pluronic f-127 is some times used to promote dispersion of the rather nonpolar snarf am acetate esters into buffers. 

   as initial loading conditions, we recommend incubating cells in 1～10 µm snarf am acetate for 30 minutes at the optimum temperature for the specific cell type of interest. after loading, cells should be washed before commencing ph measurements. for loading brain slices, incubation for 60 minutes in artificial cerebrospinal fluid(acsf) containing 20µm carboxy snarf-1 am acetate and 4% (w/v) pluronic f-127 followed by a further 30 minute incubation in dye-free acsf is recommended.