I am using a protocol from Dhindsa et al., 1981 for SOD, taking OD 560 nm. How do I calculate the SOD activity?
Hi Priyanka:
If you read the reaction absorbance at 0 and 2min, you can use below calculation for the enzyme activity.
SOD activity (U/mL) = ((Vp-Vc)/Vp)*60
Vp=OD sample at 2min - OD blank at 2min
Vc=OD sample at 0min -OD blank at 0min (start time)
e.g.
Vp=0.0759 and Vc=0.0183
SOD activity (U/mL) = ((0.0759-0.0183)/0.0759)*60= 45.52 U/ml
best
mehdi
e.g. SOD activity 45.5 U/ml and the same samle has protein concentration 2mg/ml it means:
(45.5 U/ml)/(2mg/ml) = 22.7 U/mg protein
Does any body clarify how to calculate Peroxidase, Superoxide dismutase and catalase in heat stressed rice genotypes
Mehdi Hedayati dear colleague I dont understand ehy do you use 60 as a dilution factor. I reeally aprreciate if you could explain with more details-
thanks
Dear Daniela,
It is not dilution factor, it is conversion factor.
According Beer-Lamber Low, absorbance is proportion to concentration and length of light path.
If you consider molar absorbance of the chromogen (conversion factor), the absorbance will equal equation.
A=absorbance
C= concentration
L= length of light path.
A~L.C
e=molar coefficient
A=e.L.C
e for SOD assay is 60
e=60 for this reaction (SOD reaction).
OK?
Best
Mehdi
Dear Mehdi Hedayati how to convert % inhibition of SOD to SOD activity (U/L)?
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