![Figure 3. In situ calibration of CoroNaGreen. (A) Color-coded FL images of HEK cells loaded with CoroNaGreen-AM. Blue colors represent low [Na+], and red colors represent high [Na+] as indicated by the color-coding bar below the image. First image (left) was obtained in ACSF, after which cells were exposed to calibration solutions containing [Na+] ranging from 0–150 mM as indicated. (B) Mean values of τAVG ± SD in ROIs, representing the cytosol, nucleus, and perinuclear region (PNR). Data are fit using a sigmoidal function. Note that values for PNR are consistently well above those for cytosol and nucleus for [Na+] ≤50 mM. (C) Mean values of τAVG ± SD in ROIs obtained from cytosol and nucleus and a sigmoidal fit of the data revealing a Kd of 79.9 mM. (D) Left: FL image of HEK cells, color-coded as in A. Right: Same image with regions of interest for cytosol (green), nucleus (blue) and perinuclear regions (red) indicated. (E) Box plot showing mean [Na+] (square), SD (box), and 5/95 percentiles (whiskers) in the cytosol, nucleus, and PNRs of HEK cells. (A and D) Scale bars, 20 µm. (E) ***, P ≤ 0.001.](https://cdn.rupress.org/rup/content_public/journal/jgp/151/11/10.1085_jgp.201912404/7/jgp_201912404_fig3.jpeg?Expires=1767722670&Signature=wUX9uF1ZMytOJ2o4P1flumPSX3qfC3gDPJ6V4NLg9ucDqqCp5I74URGCzQLGcTpZgZQwj9KTo7Jxzb9KyAJR1Abbt~mSD3e0B9bR0~NRqOE86~0FjA5-1CUnLCmoO1~tUEBqdX~wBMsd9ghk2Gx~ENaWoanUBuSwqroX8S0l-3aOd3-FEEiKqPeYpIyFqSg0kRrlpvd3ogZU0mKI0hPHVt861Dq4wXom~jE8wtCu5f3yVTp0C8QXRdspaSM7Xek88NTrkq9vggLlbbGzwWk--PUnIAbSwbRv4HoGibMV4Xe8IRLyypB2P4MT4QeJ4lBXwQHZ5JdnZAOEQf8FkQhNmQ__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
In situ calibration of CoroNaGreen. (A) Color-coded FL images of HEK cells loaded with CoroNaGreen-AM. Blue colors represent low [Na+], and red colors represent high [Na+] as indicated by the color-coding bar below the image. First image (left) was obtained in ACSF, after which cells were exposed to calibration solutions containing [Na+] ranging from 0–150 mM as indicated. (B) Mean values of τAVG ± SD in ROIs, representing the cytosol, nucleus, and perinuclear region (PNR). Data are fit using a sigmoidal function. Note that values for PNR are consistently well above those for cytosol and nucleus for [Na+] ≤50 mM. (C) Mean values of τAVG ± SD in ROIs obtained from cytosol and nucleus and a sigmoidal fit of the data revealing a Kd of 79.9 mM. (D) Left: FL image of HEK cells, color-coded as in A. Right: Same image with regions of interest for cytosol (green), nucleus (blue) and perinuclear regions (red) indicated. (E) Box plot showing mean [Na+] (square), SD (box), and 5/95 percentiles (whiskers) in the cytosol, nucleus, and PNRs of HEK cells. (A and D) Scale bars, 20 µm. (E) ***, P ≤ 0.001.
