Ascorbate

From Bioblast
Jump to: navigation, search
Bioblasts - Richard Altmann and MiPArt by Odra Noel
MitoPedia         Terms and abbreviations         Concepts and methods         MitoPedia: SUIT         MiP and biochemistry         Preprints and history



MitoPedia

Ascorbate

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; FW = 198.1.
Caution: Light sensitive (store solution in a dark glass vial).


Preparation of 800 mM stock solution (dissolved in H2O) for 2-mL O2k-chamber:
  1. Weigh 1.584 g of ascorbate sodium salt and dissolve in 10 mL H2O
  2. To prevent autoxidation, adjust pH to approx. 6 with ascorbic acid (a 137.6 mg.mL-1 solution of pH 2).
  3. Divide into 0.2 mL portions.
  4. 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:
  1. Weigh 1.980 g of ascorbate sodium salt and dissolve in 10 mL H2O
  2. To prevent autoxidation, adjust pH to approx. 6 with ascorbic acid (a 137.6 mg.mL-1 solution of pH 2).
  3. Divide into 0.2 mL portions.
  4. 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