- high-resolution terminology - matching measurements at high-resolution
PH calibration buffers
Description
pH calibration buffers are prepared to obtain two or more defined pH values for calibration of pH electrodes and pH indicator dyes.
Modified Hanks buffer
| Substance | Formula | Concentration [mM] |
|---|---|---|
| Calcium chloride dihydrate | CaCl2 * 2 H2O | 0.42 |
| Imidazole | C3H4N2 | 2.0 |
| Potassium chloride | KCl | 2.4 |
| Magnesium chloride hexahydrate | MgCl2*6 H2O | 0.49 |
| Sodium chloride | NaCl | 137 |
- pH adjusted to 7.1 at 30 °C.
- pH adjusted with KOH or HCl to create a buffer series: (pH values at 25 °C)
- A (pH 3.3),
- B (pH 6.1)
- C (pH 6.6)
- D (pH 6.9)
- E (pH 7.3)
- F (pH 7.5)
- G (pH 11.1) pH 10.1 at 37° did not represent the basic endpoint for carboxy-SNARF-1.
- Calibration
- Basic endpoint (for SNARF): fluorophore completely deprotonated.
- Acidic endpoint (for SNARF): fluorophore completly protonated.
- Calibration
Media with low buffering capacity
- Media with low pH buffering capacity are required for measurement of proton flux in intact cells. Commercially available variants of RPMI1640 that contain neither hydrogen carbonate nor HEPES may constitute a starting point, see e.g. Sigma Product number 6504 (not tested by Oroboros Instruments, due to the inclusion of phenol red this medium may (or may not) be problematic for fluorescence).
MitoPedia methods:
Respirometry,
Fluorometry
MitoPedia topics:
Media for respirometry
