DAPI 5 mg/mL stock (nuclear stain) recipe
A fluorescent DNA stain that marks nuclei blue; dilute 1:5000 (1 µg/mL) and stain for 5 min.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| DAPI dihydrochloride | 5 mg | 5 mg/mL (14.3 mM) |
| Water (distilled) | to final volume |
Steps
- Dissolve in water (or DMF), warming gently if needed.
- Aliquot in foil-wrapped tubes at −20 °C.
- Dilute 1:5000 in PBS, stain 5 min at room temperature and wash.
Good to know
- UV excitation (~358 nm) → blue emission (~461 nm).
- For live cells use the more permeant Hoechst 33342.
⚠ Safety It binds DNA and may be mutagenic — wear gloves.
FAQ
Do I need this if my mountant contains DAPI?
No — a DAPI mountant stains on its own, though it may take a few hours to even 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.