30% acrylamide/bis-acrylamide (29:1) recipe
The 30% acrylamide stock for casting SDS-PAGE gels. Because of its toxicity, a commercial solution is recommended where possible.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| Acrylamide | 29 g | 29% |
| N,N′-methylene-bis-acrylamide | 1 g | 1% |
| Water (distilled) | to final volume |
Steps
- Weigh the powders in a fume hood with mask and gloves.
- Dissolve in about 60% of the final volume of water (gentle warming is fine) and make up to volume.
- Filter and store dark at 4 °C (about a month).
Good to know
- A 37.5:1 ratio (0.8 g bis) gives slightly larger pores; both 29:1 and 37.5:1 are common for SDS-PAGE.
⚠ Safety Unpolymerised acrylamide is a neurotoxin — wear gloves and prefer ready-made solutions to powder. Polymerised gel is much safer.
FAQ
Can I use an old stock?
It hydrolyses to acrylic acid over time, causing poor polymerisation and fuzzy bands. Replace it if yellowed or older than 1–2 months.
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.