Resazurin sodium (solution)

Resazurin sodium (Diazoresorcinol 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^[2][3]
1.1 Stock solution
Storage: Store at -20°C or -80°C in dark after aliquoting. Avoid repeated freezing and thawing.
1.2 Preparation of working solution
Dilutewith PBS or serum-free medium.The corresponding stock solution can be diluted according to the actual situation. Note that if the solvent is DMSO, the cytotoxicity of DMSO must be considered, and a solvent control should be prepared; if the solvent is pure water, the working solution needs to be filtered and sterilized before adding cells.
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.