Hi 

I hope that following link help you.

Regards

http://www.allergyresearchgroup.com/antioxidant-formulas/

Antioxidant standard formula? Are you looking for protocol to assay the antioxidant enzymes from tissue?

It is not clear from your question what you actually want to know. If you are looking for assaying the efficacy of these enzymes as anti-oxidant, you can perform MDA assay, commet assay, protein oxidation assay, peroxide formation assay etc.

Yes, your question is not clear, may elaborate, what you want.

http://www.allergyresearchgroup.com/antioxidant-formulas/

kindly visit the linked website. I hope your problem will be solved 

i think what u asked is one standard formula for all the assays...... there is no standard formula for all these assays, however, each of them has different formula based on the protocol you follow and how you want to express (per  gram tissue, per mg protein etc,)

Thanks.

https://www.researchgate.net/deref/http%3A%2F%2Fwww.allergyresearchgroup.com%2Fantioxidant-formulas%2F

how to calculate the GPx activity after getting absorbance of blank and samples? I also want to know that Decrease in absorbance is directly or inversely proportional to GPx activity?