1% formaldehyde denaturing agarose gel (RNA) recipe
A denaturing gel that unfolds RNA secondary structure so it runs by size — for Northern blots and RNA integrity checks.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| Agarose | 1 g | 1% |
| DEPC-treated water | 72 mL | |
| 10X MOPS buffer | 10 mL | 1X |
| 37% formaldehyde | 18 mL | ≈2.2 M |
Steps
- Melt the agarose in the water until completely clear.
- Cool to 60 °C, then add 10X MOPS and formaldehyde in a fume hood and mix.
- Pour and let set for at least 30 min inside the fume hood.
- Run in 1X MOPS buffer (5–7 V/cm).
Good to know
- Lower-formaldehyde versions (0.66 M final, ≈1.8%) are also widely used.
⚠ Safety Formaldehyde is carcinogenic and irritating — cast and run the gel in a fume hood.
FAQ
What does intact RNA look like?
Mammalian total RNA shows a 28S band about twice as intense as 18S, without smearing.
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.