Miniprep solution 1 (resuspension, P1) recipe
The first solution of alkaline-lysis plasmid miniprep: resuspends bacteria while RNase A digests RNA. 50 mM Tris-HCl pH 8.0, 10 mM EDTA, 100 µg/mL RNase A.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| 1 M Tris-HCl (pH 8.0) | 5 mL | 50 mM |
| 0.5 M EDTA (pH 8.0) | 2 mL | 10 mM |
| RNase A (DNase-free) | 10 mg | 100 µg/mL |
| Water (distilled) | to final volume |
Steps
- Mix Tris and EDTA with water and autoclave.
- Add RNase A once cool.
- Store at 4 °C (about 6 months).
Good to know
- Use 250 µL per pellet from 1.5–5 mL culture and resuspend completely.
- The classic Sambrook Solution I also contains 50 mM glucose.
FAQ
What if I have no RNase A?
RNA will contaminate the plasmid and inflate the measured concentration; it appears as a low smear on gels.
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.