Difference between revisions of "Cyanide"

Revision as of 15:53, 19 April 2019

high-resolution terminology - matching measurements at high-resolution

Cyanide

Description

Cyanide (usually added as KCN) is a competitive inhibitor of cytochcrome c oxidase (CIV). Inhibition is reversed by pyruvate and high oxygen levels.

Abbreviation: KCN

Reference: MiPNet09.12

MitoPedia topics: Inhibitor

Application in HRR

Inhibitor titrations, CIV-assay, alternative oxidase and ROX

Cyanide and determination of residual oxygen consumption (ROX).
Complex IV assay
alternative oxidase

Preparation of 20 mM KCN stock (in 45mM Trizma base)

Kcn(KCN): Fluka 60178, 100 g, store at R.T.; FW = 65.12., Trizma base: Sigma T6066, 100 g, store at R.T.; FW = 121.14

Caution: KCN is photosensitive and hygroscopic; HCN is volatile and very toxic! It is recommended to prepare fresh KCN solution although it can be safely stored at -20°C. To avoid KCN evaporation, it is recommended to use alkaline buffers (such as 45 mM Trizma base, pH >10).

Preparation of 45 mM Trizma base:

Weigh 545 mg of Trizma base
Dissolve it in 100 mL of H₂0.

Preparation of 20 mM KCN:

Weigh 5.2 mg of KCN and dissolve in 4 ml of 45 mM Trizma base.
Divide into 500 µl aliquots (use dark glass vials).
Store frozen at -20 °C.

O2k manual titrations MiPNet09.12 O2k-Titrations

Titration volume: 100 µl of 20 mM stock (2 ml O2k-chamber).
Final concentration: 1 mM.

@@ Line 19: / Line 19: @@
-=== Preparation of 20 mM KCN stock (in 50mM Trizma base)===
+=== Preparation of 20 mM KCN stock (in 45mM Trizma base)===
 :::: '''Kcn'''(KCN): Fluka 60178, 100 g, store at R.T.; FW = 65.12., '''Trizma base''': Sigma T6066, 100 g, store at R.T.; FW = 121.14
-:::: <span style="color:#8B008B"> '''Caution:''' KCN is photosensitive and hygroscopic; HCN is volatile and very toxic! It is recommended to prepare fresh KCN solution although it can be safely stored at -20°C. To avoid KCN evaporation, it is recommended to use alkaline buffers (such as 50 mM Trizma base, pH 9).</span>
+:::: <span style="color:#8B008B"> '''Caution:''' KCN is photosensitive and hygroscopic; HCN is volatile and very toxic! It is recommended to prepare fresh KCN solution although it can be safely stored at -20°C. To avoid KCN evaporation, it is recommended to use alkaline buffers (such as 45 mM Trizma base, pH >10).</span>
-:::: '''Preparation of 50 mM Trizma base:'''
+:::: '''Preparation of 45 mM Trizma base:'''
-::::# Weigh 605.7 mg of Trizma base
+::::# Weigh 545 mg of Trizma base
 ::::# Dissolve it in 100 mL of H<sub>2</sub>0.
 :::: '''Preparation of 20 mM KCN:'''
-::::# Weigh 5.2 mg of KCN and dissolve in 4 ml of 50 mM Trizma base.
+::::# Weigh 5.2 mg of KCN and dissolve in 4 ml of 45 mM Trizma base.
 ::::# Divide into 500 µl aliquots (use dark glass vials).
 ::::# Store frozen at -20 °C.