10% sodium azide (NaN₃) recipe
A preservative stock added at 0.02–0.05% to stop microbial growth in antibody solutions and buffers. Highly toxic.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| Sodium azide | 1 g | 10% (w/v) |
| Water (distilled) | to final volume |
Steps
- Weigh the powder in a fume hood wearing gloves and a mask.
- Dissolve in water and make up to volume.
- Label "TOXIC" and store at room temperature.
Good to know
- For 0.02%, add the 10% stock 1:500 (200 µL per 100 mL).
- Azide inhibits HRP — never add it to HRP antibodies or substrate solutions.
⚠ Safety Very toxic by ingestion or inhalation; releases toxic gas with acid and forms explosive salts in copper or lead plumbing — never pour down the sink.
FAQ
Can I use it with live cells?
No — azide blocks respiration. Use azide-free antibodies for live cells or dialyse it out.
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.