Ascorbate: Difference between revisions
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== Application in [[HRR]] == | == Application in [[HRR]] == | ||
:::: '''As: Ascorbate sodium salt''' (Sodium L-ascorbate); Sigma A 7631, 100 g, store at RT; | :::: '''As: Ascorbate sodium salt''' (Sodium L-ascorbate); Sigma A 7631, 100 g, store at RT; M = 198.1 gยทmol<sup>-1</sup>. | ||
:::: <span style="color:#8B008B"> '''Caution:''' Light sensitive (store solution in a dark glass vial).</span> | :::: <span style="color:#8B008B"> '''Caution:''' Light sensitive (store solution in a dark glass vial).</span> |
Revision as of 12:46, 12 February 2021
Description
In respiratory assays for cytochrome c oxidase activity (Complex IV, CIV), ascorbate is added as regenerating system for maintaining TMPD in a reduced state. As has to be titrated into the respiration medium prior to the addition of TMPD, otherwise the reaction velocity of autoxidation is permanently elevated.
Abbreviation: As
Reference: MiPNet06.06
Application in HRR
- As: Ascorbate sodium salt (Sodium L-ascorbate); Sigma A 7631, 100 g, store at RT; M = 198.1 gยทmol-1.
- Caution: Light sensitive (store solution in a dark glass vial).
- Preparation of 800 mM stock solution (dissolved in H2O) for 2-mL O2k-chamber:
- Weigh 1.584 g of ascorbate sodium salt and dissolve in 10 mL H2O
- To prevent autoxidation, adjust pH to approx. 6 with ascorbic acid (a 137.6 mg.mL-1 solution of pH 2).
- Divide into 0.2 mL portions.
- Store frozen at -20 ยฐC.
- ยปO2k manual titrations: MiPNet09.12
- Titration volume (2-mL O2k-chamber): 5 ยตL using a 25 ยตL Hamilton syringe.
- Final concentration: 2 mM.
- Preparation of 1000 mM stock solution (dissolved in H2O) for 0.5-mL O2k-chamber:
- Weigh 1.980 g of ascorbate sodium salt and dissolve in 10 mL H2O
- To prevent autoxidation, adjust pH to approx. 6 with ascorbic acid (a 137.6 mg.mL-1 solution of pH 2).
- Divide into 0.2 mL portions.
- Store frozen at -20 ยฐC.
- ยปO2k manual titrations: MiPNet09.12
- Titration volume (0.5-mL O2k-chamber): 1 ยตL using a 10 ยตL Hamilton syringe.
- Final concentration: 2 mM.
MitoPedia topics:
Substrate and metabolite