Ascorbate: Difference between revisions
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:::: <span style="color:#8B008B"> '''Caution:''' Solutions of ascorbic acid are rapidly oxidized in air and in alkaline media; the compound should be protected from air and light. See 'ascorbid acid' on [https://pubchem.ncbi.nlm.nih.gov/compound/54670067 PubChem]</span> | :::: <span style="color:#8B008B"> '''Caution:''' Solutions of ascorbic acid are rapidly oxidized in air and in alkaline media; the compound should be protected from air and light. See 'ascorbid acid' on [https://pubchem.ncbi.nlm.nih.gov/compound/54670067 PubChem]</span> | ||
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:::: '''Preparation of 800 mM stock solution''' (dissolved in H<sub>2</sub>O): | :::: '''Preparation of 800 mM stock solution''' (dissolved in H<sub>2</sub>O): | ||
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:::: '''Preparation of 800 mM stock solution''' (dissolved in H<sub>2</sub>O) for '''2-mL O2k-chamber''': | :::: '''Preparation of 800 mM stock solution''' (dissolved in H<sub>2</sub>O) for '''2-mL O2k-chamber''': | ||
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::::# Weigh 990.5 g of ascorbate sodium salt and dissolve in 3 mL H<sub>2</sub>O | ::::# Weigh 990.5 g of ascorbate sodium salt and dissolve in 3 mL H<sub>2</sub>O | ||
::::# To prevent autoxidation, adjust pH to approx. 6 with 1 M HCl. | ::::# To prevent autoxidation, adjust pH to approx. 6 with 1 M HCl. | ||
::::# Adjust final volume to 5 mL and divide into 0.2 mL portions in dark vials. | ::::# Adjust final volume to 5 mL and divide into 0.2 mL portions in dark vials. | ||
::::# Store frozen at -20 °C. | ::::# Store frozen at -20 °C. | ||
Revision as of 11:15, 22 March 2021
- high-resolution terminology - matching measurements at high-resolution
Ascorbate
Description
In respiratory assays for cytochrome c oxidase activity (Complex IV, CIV), ascorbate is added as regenerating system to maintain TMPD in a reduced state. It has to be titrated into the respiration medium prior to the addition of TMPD, otherwise the autoxidation reaction velocity 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 g·mol-1.
- Caution: Solutions of ascorbic acid are rapidly oxidized in air and in alkaline media; the compound should be protected from air and light. See 'ascorbid acid' on PubChem
- Preparation of 800 mM stock solution (dissolved in H2O) for 2-mL O2k-chamber:
- Weigh 792.4 g of ascorbate sodium salt and dissolve in 3 mL H2O
- To prevent autoxidation, adjust pH to approx. 6 with 1 M HCl (approx. 85 µL).
- Adjust final volume to 5 mL and divide into 0.2 mL portions in dark vials.
- Store frozen at -20 °C.
- »O2k manual titrations: MiPNet09.12
- Titration volume (2-mL O2k-chamber): 5 µL using a 25 µL Hamilton syringe.
- Final concentration: 2 mM.
- Preparation of 1000 mM stock solution (dissolved in H2O) for 0.5-mL O2k-chamber:
- Weigh 990.5 g of ascorbate sodium salt and dissolve in 3 mL H2O
- To prevent autoxidation, adjust pH to approx. 6 with 1 M HCl.
- Adjust final volume to 5 mL and divide into 0.2 mL portions in dark vials.
- Store frozen at -20 °C.
- »O2k manual titrations: MiPNet09.12
- Titration volume (0.5-mL O2k-chamber): 1 µL using a 10 µL Hamilton syringe.
- Final concentration: 2 mM.
MitoPedia topics:
Substrate and metabolite
