Resazurin sodium  (Synonyms: Diazoresorcinol sodium)

Resazurin sodium (Diazoresorcinol sodium) is a non-toxic, stable, membrane-permeable blue non-fluorescent dye (faintly fluorescent). Resazurin sodium is used as a redox indicator, can be reduced to pink, highly fluorescent Resorufin (Ex=530-560 nm, Em=590 nm) in living cells. Resazurin sodium can be used for the detection of cell viability, toxicity, proliferation, migration and invasion in cells (human, plant and animal, bacterial and fungal)^[1][2][3].

Resazurin sodium is commonly used to measure bacterial and eukaryotic cell viability through its reduction to the fluorescent product resorufin. No viable bacteria are detected 24 h post-inoculation following inclusion of Resazurin sodium in TSBc cultures of F. tularensis LVS at the concentration of 44 μM. Lowering the Resazurin sodium concentration to as little as 4.4 μM still results in a 10-fold reduction in viable F. tularensis LVS compare to growth medium alone. Both Resazurin sodium treatments result in a significant decrease in viable F. tularensis LVS bacteria over 22 h. Treatment with Resazurin sodium significantly reduces the number of viable F. tularensis LVS bacteria in HEK293 cells 22 h post-infection^[1].

Guide (Following is our recommended protocol. This protocol only provides a guideline, and should be modified according to your specific needs).
1. Solution preparation
1.1 Preparation of stock solution
Solvent: DMSO or ddH2O
Concentration: 1 mg/mL (optimized according to the experiment).
Storage: Store at -20°C or -80°C in dark after aliquoting. Avoid repeated freezing and thawing.
1.2 Preparation of working solution
Dilute to 1 μg/mL with PBS or serum-free medium (optimized according to the experiment).
Note: The working solution should be prepared and used immediately. Keep it away from light.

2. Cell viability
1. Defrost the Resazurin sodium solution in a 37°C water bath.
2. Place the cells on a 96-well plate, and washed by PBS (avoid light).
3. Remove the PBS wash, then add 100 μL (1 μg/mL) of Resazurin sodium solution.
4. Place the plate, in the incubator for 30 min (incubation time depends on cell type and cell number).
5. Measure Resazurin sodium fluorescence (Ex = 530-560 nm, Em = 590 nm) using a microplate reader.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

251.17

C₁₂H₆NNaO₄

62758-13-8

Solid

Light brown to black

O=C1C=CC2=[N+]([O-])C3=C(C=C(O[Na])C=C3)OC2=C1

Room temperature in continental US; may vary elsewhere.

4°C, sealed storage, away from moisture and light

*In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture and light)

* Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.
Storage method and period of stock solution: -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture and light). When stored at -80°C, please use it within 6 months. When stored at -20°C, please use it within 1 month.

* Note: If you choose water as the stock solution, please dilute it to the working solution, then filter and sterilize it with a 0.22 μm filter before use.

• [1]. Schmitt DM, et al. The use of resazurin as a novel antimicrobial agent against Francisella tularensis. Front Cell Infect Microbiol. 2013 Dec 6;3:93.  [Content Brief]

  [2]. Silva FSG, et al. Determination of Metabolic Viability and Cell Mass Using a Tandem Resazurin/Sulforhodamine B Assay. Curr Protoc Toxicol. 2016 May 4;68:2.24.1-2.24.15.  [Content Brief]

  [3]. Rampersad SN. Multiple applications of Alamar Blue as an indicator of metabolic function and cellular health in cell viability bioassays. Sensors (Basel). 2012;12(9):12347-60.  [Content Brief]