Description
⚖️ MES Buffer (2-(N-Morpholino)ethanesulfonic acid) — a Good’s buffer (pKₐ 6.10) that stabilises TC medium pH and prevents the acidification drift that occurs in actively growing cultures.
| 🧪 CAS | 4432-31-9 | ⚖️ MW | 195.24 g/mol |
| 🔬 Grade | Biological/TC Grade | 🌡️ Storage | RT, dry, sealed |
⚖️ The pH drift problem
Actively growing plant cultures acidify their medium through: H⁺ extrusion via plasma membrane H⁺-ATPase, organic acid secretion, and ammonium assimilation. Medium pH can fall from 5.7 to <4.5 within 2–3 weeks — inhibiting growth and nutrient uptake. MES buffer (0.5–2 g/L) suppresses this drift without the ionic interference of phosphate buffers.
⚖️ Working concentrations
| Use | Concentration | Notes |
|---|---|---|
| General TC medium pH stabilisation | 0.5–1 g/L (2.6–5.1 mM) | Adjust to pH 5.7 before autoclaving |
| Protoplast culture medium | 1–2 g/L | Critical for osmotically sensitive cells |
| Root physiology experiments | 0.5–2 g/L | Where pH stability is essential |
| High-ammonium media | 1–2 g/L | Ammonium assimilation causes pH drop |
💡 MES does not interfere with iron chelation (unlike phosphate) and is non-metabolised by plants. It survives autoclaving intact. Worth adding to any medium where you observe pH-related culture problems.
Reviews
There are no reviews yet.