2% Alizarin Red S (mineralisation stain) recipe
Stains calcium deposits from osteoblast differentiation red: 2% Alizarin Red S, pH 4.1–4.3.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| Alizarin Red S | 1 g | 2% (w/v) |
| Water (distilled) | to final volume |
Steps
- Dissolve in about 80% of the final volume of water.
- Adjust to pH 4.1–4.3 with 0.1–0.5% ammonium hydroxide (pH is critical).
- Bring to the final volume with water.
- Filter and store dark at 4 °C (about a month).
- Stain fixed cells for 20–30 min and wash several times with water.
Good to know
- Quantify by extracting with 10% acetic acid or 10% cetylpyridinium chloride and reading 405 nm (or 562 nm).
FAQ
Everything is stained red.
Usually the pH is off or washing was insufficient — recheck pH 4.2 and wash more.
This is a widely used standard composition. Amounts depend on the hydrate form and purity of your reagents — check the formula weight (FW) on the bottle and follow your institution's safety rules and the manufacturers' instructions.