Sunday, September 9, 2007

10th Week of SIP- Lab Techniques (Research)

Hello all!
Hope you guys are enjoying work. Haha.

Anyway, today I'll be talking about the SOD Assay.

Superoxide Dismutase (SOD) Assay

What is SOD?
SOD is a metalloenzyme that catalyzes the dismutation of superoxide radicals (O2•-) into hydrogen peroxide (H2O2) and oxygen (O2).
Superoxide radicals are produced during metabolism in the mitochondria, muscle contraction, and as well as by NADPH oxidase during infections. Accumulation of these radicals would then lead to oxidative stress and eventually to diseases like Parkinson's disease, atherosclerosis etc.
Thus, with SOD present, it can defend against oxidative stress.

Other than SOD, Gluthathione peroxidase and Catalase also helps to protect against oxidative stress.

Liver supernatant will be used for this assay.

Principle of SOD Assay

The SOD Assay also uses tetrazolium salt to detect superoxide radicals. Xanthine oxidase present in the reaction mixture interacts with the radicals, which reduces the tetrazolium salt into formazan. The presence of SOD will reduce the amount of radicals, and in turn reduce the amount of formazan formed. Thus, increased levels of SOD, will lead to reduced levels of formazan.

After adding the respective reagents according to the protocol, abs is read using an ELISA plate reader at 450nm.


Fig. 1: Principle of SOD Assay

In other words: ↑SOD, ↓O2•-, ↓ formazan formed, ↓ Abs

That's it!
Take care guys~

Charmaine Tan
TG01

7 comments:

Star team said...
This comment has been removed by the author.
Star team said...

Hey,

What's the clinical significance of this test? Thanks.

Yong Yang
TG02

J.A.M.M.Y.S said...

Hi charmaine

i was just wondering the use of this test in your major project? what's the relationship? :)

shahirah
TG01

we are the XiaoBianTai-7! said...

Hey Y2!

This test is not a test for clinical usage. It's an in vitro test used, for example, to test whether a particular food is able to enhance the antioxidant activity.
Hope it answers your question!

we are the XiaoBianTai-7! said...

Hello sha!

I'm testing whether this functional food is able to enhance the SOD activity.
Antioxidant mechanism defence is also part of the immunity, because it helps to get rid of the radicals, which in turn, prevents diseases caused by oxidative stress.
Hope that answers your question!

Kent said...

Hi Charmaine,

Thanks for the short and sweet posting. Really saves time for all of us! =)

A few questions for u. Am I right to say that every cell in the body produces SOD to fight off oxidative stress? In that case, can we use other cells (instead of liver cells) to measure SOD levels?

Hm.. I don't really understand what you mean by "liver supernatant". Do u mean liver cell lysate supernatant?

Thanks!
Kent
TG01

we are the XiaoBianTai-7! said...

Hello kent! =DD

Haha, it's either I blog about this or I blog about cleaning fridges. -.-

Yup, basically SOD is to protect against oxidative stress.
Sure, we can use other cells, for example, phaogycytes/monocytes, as these cells contain SOD to dismutate oxygen radicals formed during infections.

Liver supernantant meaning the cell lysate. But what I do is just to crush the whole liver and spin it down to collect the supernatant.

Take care~