Resazurin sodium salt 199303 Sigma

Resazurin Sodium Salt: Overview, Mechanism, and Technical Specifications

Resazurin Sodium Salt (CAS Number: 62758-13-8), systematically known as 7-Hydroxy-3H-phenoxazin-3-one-10-oxide sodium salt, is a reliable, non-destructive oxidation-reduction (redox) indicator widely used in cell biology, pharmacology, and microbiology. It serves as a gold-standard reagent for assessing cell viability, cytotoxicity, and proliferation kinetics across various mammalian, bacterial, and fungal cell models.

Owing to its high sensitivity, water solubility, and non-toxic profile at standard working concentrations, Resazurin enables real-time, continuous monitoring of cellular metabolic health without compromising cell integrity.

Technical Specifications & Chemical Properties

Biochemical Mechanism of Action

The assay mechanism relies on the intrinsic metabolic capability of viable cells to reduce the non-fluorescent dye into a highly fluorescent product via mitochondrial and cytosolic dehydrogenases coupled with electron carriers (NADHNADHNADH and NADPHNADPHNADPH):

Oxidized State: In cell culture medium, Resazurin remains in a stable, dark blue, weakly fluorescent state.

1. Intracellular Bioreduction: Passive diffusion brings the reagent into metabolically active cells, where intracellular electron transfer reactions reduce the phenoxazine core.
2. Fluorescent Signal Generation: The resulting reduction product, Resorufin, exhibits bright pink coloration and intense red fluorescence. The signal magnitude correlates linearly with the number of viable, metabolically active cells.

Analytical Comparison: Resazurin vs. Conventional Assays

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Research & Diagnostic Applications

1. High-Throughput Cytotoxicity & Drug Screening

Enables quantitative evaluation of anticancer drug candidates, novel chemical entities, engineered nanomaterials, and environmental toxicants across diverse cell lines with minimal operational steps.

2. Cell Proliferation & Kinetic Studies

Facilitates continuous, longitudinal tracking of cell division dynamics, stem cell differentiation, and growth factor responses over extended culture intervals.

3. Antimicrobial Susceptibility Testing (MIC Determination)

Provides rapid, clear endpoint determinations for Minimum Inhibitory Concentration (MIC) assays against Gram-positive, Gram-negative bacteria, yeasts, and filamentous fungi in 96-well microplate formats.

4. 3D Cell Models & Organoids

Due70-600 nm Emission: ~585-590 nm (Ex: 530-560 nm)