I had done the Reduced Glutathione assay in rat liver tissue (10% homogenate in PO4 buffer, pH 7.4) using Beutler et al., 1963 by DTNB method. The results are comes around more than 300 units. But the previous articles showed below 40 or 20 units (mug/mg of proteins). So, can anyone please help me to calculate the GSH assay? Along with I had mentioned my assay details.

Thanks in advance.

Reagents

Blank

Test

Sample

*

0.2

5% TCA

*

0.8

Allow to stand at room temperature for 5 mins. Centrifuge at 3000 rpm for 10 min.

Supernatant

*

0.2

5% TCA

0.2

*

Phosphate Solution

0.8

0.8

0.6mM DTNB

2.0

2.0

Leave for 60 sec – forms yellow colour

↓

Read @ 412 nm