20X SSC (saline-sodium citrate) recipe
The saline-citrate buffer for Southern/Northern blots, in situ hybridisation and FISH washes. 20X = 3 M NaCl, 0.3 M sodium citrate, pH 7.0.
🧮 Volume calculator
| Component | Amount | Final concentration (1X) |
|---|---|---|
| NaCl | 175.3 g | 3 M (20X) |
| Trisodium citrate dihydrate | 88.2 g | 0.3 M (20X) |
| Water (distilled) | to final volume |
Steps
- Dissolve in about 80% of the final volume of water.
- Adjust to pH 7.0 with a few drops of HCl.
- Bring to the final volume with water.
- Autoclave (121 °C, 20 min) and store at room temperature.
Good to know
- Stringency increases as SSC falls and temperature rises (e.g. 2X SSC RT → 0.1X SSC 65 °C).
FAQ
How does SSPE differ?
SSPE uses phosphate instead of citrate plus EDTA, giving steadier pH in formamide-rich hybridisations.
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.