SoNa™ 520

1. Add 50 µL NaCl Standards or test samples

2. Add 50 µL SoNa™ 520 working solution.

3. Incubate at RT for 5-10 minutes

4. Monitor the fluorescence at Ex/Em=490/525 nm

The following protocol is an example for quantifying sodium content using SoNa™ 520. The DMSO stock solution should be handled with particular caution as DMSO is known to facilitate the entry of organic molecules into tissues.

Unless otherwise noted, all unused stock solutions should be divided into single-use aliquots and stored at -20 °C after preparation. Avoid repeated freeze-thaw cycles

1. Add DMSO into SoNa™ 520 vial (Component A) to make 2 to 5 mM stock solution.

   Note: Make a single unused SoNa™ 520 stock solution aliquot and store at ≤ -20 º C. Protect from light and avoid repeated freeze-thaw cycles.

1. Prepare 10 to 20 µM SoNa™ 520 working solution into 5 mL of Tris Buffer (pH∼7.5). Protect the working solution from light by covering it with foil or placing it in the dark.

   Note: For best results, this solution should be used within a few hours of its preparation.

   Note: 5 mL of working solution is enough for 100 tests.

The following protocol only provides a guideline and should be modified according to your specific needs.

SS=NaCl Standards (SS1 - SS7, 40 to 0.625 mM, 2X dilutions); BL=Blank Control; TS=Test Samples

1. Prepare NaCl standards (SS), blank controls (BL), and test samples (TS) according to the layout provided in Tables 1 and 2. For a 384-well plate, use 25 µL of reagent per well instead of 50 µL.

2. Add 50 µL of SoNa™ 520 working solution to each well of NaCl standards, blank control, and test samples to make the assay volume of 100 µL/well. For a 384-well plate, add 25 µL into each well instead, for a total volume of 50 µL/well.

3. Incubate the reaction at room temperature for 5 to 10 minutes, protected from light.

4. Monitor the fluorescence increase with a fluorescence microplate reader at Ex/Em = 490/525 nm (cut off at 515 nm).