XTT sodium is a cell viability detector that can be metabolized by mitochondrial dehydrogenase in live cells to produce a highly colored water-soluble formic acid product.

Assaying Cell Viability Using XTT Sodium [2]
1. Seed cells to be tested into a 96-well plate at 100 μL per well and incubate at 37°C for 40 hours.
2. Dissolve XTT sodium in culture medium to a concentration of 1 mg/mL. Dissolve PMS in phosphate-buffered saline (PBS) to a concentration of 100 mM. Add the PMS solution to the XTT solution to achieve a final PMS concentration of 25 μM. Add 25 μL of the XTT/PMS solution to each well and incubate for 4–8 hours.
3. After incubation, measure absorbance at 450 nm using a microplate reader, with a reference wavelength of 650 nm. Subtract the absorbance value of the blank control.
Precautions
(1) Prepare XTT solution immediately before use; it may be dissolved in a 60°C water bath.
(2) Use PMS solution within one month.
(3) Protect PMS and XTT solutions from light during use and storage.
(4) Adjust incubation time based on experimental results; prolonged incubation may increase background noise.

H2O: 8 mg/mL (11.88 mM), Sonication is recommended.

DMSO: 32 mg/mL (47.51 mM), Sonication is recommended.