2.4. Superoxide Dismutase (SOD) activity assay
The SOD assay was carried out using Cayman’s Superoxide Dismutase Assay Kit. 10 μL of three series of
concentrations including 500; 125; 31.25 μg/mL of GMRextract and fractions were pippeted into sample wells, then
200 μL diluted radical detector was added into each wells. For SOD standard wells, 200 μL diluted radical detector
and 10 μL standard was pippeted into the wells (tubes A-G). To intitiate the reactions, 20 μL diluted xanthine
oxidase was added into each wells. This well plate was shaked for few seconds for mixing and incubated on shaker
for 20 minutes at room temperature. Absorbance of each well was read at 450 nm curve and linearized rate (LR).
The SOD level in U/ mL was determinate by the equation below.
(%) x100
AC
AsAc
Scaveninge
200 Susy Tjahjani et al. / Procedia Chemistry 13 ( 2014 ) 198 – 203
x sample dilution
Slope
sampleLR y ercept x mL
SOD .. ( .int ). .0. 23