Coomassie blue staining solution (R-250) recipe
The classic stain that turns protein bands blue on SDS-PAGE gels: 0.1% Coomassie R-250, 40% methanol, 10% acetic acid.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| Coomassie Brilliant Blue R-250 | 500 mg | 0.1% |
| Methanol | 200 mL | 40% |
| Glacial acetic acid | 50 mL | 10% |
| Water (distilled) | to final volume |
Steps
- Dissolve the Coomassie in the methanol first.
- Add the acetic acid and water to the final volume.
- Filter through paper to remove particles and store at room temperature (reusable several times).
Good to know
- Stain the gel for 30–60 min, then destain until the background is clear.
- Sensitivity is about 50–100 ng protein per band.
⚠ Safety Methanol is toxic and flammable — use gloves in a ventilated area.
FAQ
Is there a methanol-free option?
Colloidal Coomassie G-250 methods (the "safe stain" type) avoid methanol and destain with water.
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.