Ascorbate

From Bioblast


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 L-ascorbate; C6H7NaO6), Sigma-Aldrich: A7631, store at RT, CAS: 134-03-2, M = 198.11 gΒ·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:
  1. Weigh 792.4 mg of ascorbate sodium salt and dissolve in 3 mL H2O
  2. To prevent autoxidation, adjust pH to approx. 6 with 1 M HCl (approx. 85 Β΅L).
  3. Adjust final volume to 5 mL and divide into 0.2 mL portions in dark vials.
  4. Store frozen at -20 Β°C.
Β»O2k manual titrations: MiPNet09.12
  • Titration volume (2-mL O2k-chamber): 5 Β΅L using a 25 Β΅L Hamilton syringe.
  • Final concentration: 2 mM.


Preparation of 1000 mM stock solution (dissolved in H2O) for 0.5-mL O2k-chamber:
  1. Weigh 990.5 mg of ascorbate sodium salt and dissolve in 3 mL H2O
  2. To prevent autoxidation, adjust pH to approx. 6 with 1 M HCl.
  3. Adjust final volume to 5 mL and divide into 0.2 mL portions in dark vials.
  4. Store frozen at -20 Β°C.
Β»O2k manual titrations: MiPNet09.12
  • Titration volume (0.5-mL O2k-chamber): 1 Β΅L using a 10 Β΅L Hamilton syringe.
  • Final concentration: 2 mM.


MitoPedia topics: Substrate and metabolite 

Cookies help us deliver our services. By using our services, you agree to our use of cookies.