Wednesday, October 31, 2007

18th week of SIP - Lab Techniques (Research)

Hey! Last 2nd week of SIP now aye? Soon, it'll be over! =D

Anyway, I'll be touching on this assay called Rat/Mouse Insulin ELISA Assay

Rat/Mouse Insulin ELISA Assay

Insulin is a hormone made by the beta cells in the islets of Langerhans that regulates the level of glucose in the blood.

When blood glucose level increases, insulin will be produced and released into the blood circulation.

This picture gives an overview on how insulin regulates blood glucose level.

Taken from: here.

This assay is performed in vitro.

Principle:
The basis of this assay is through sandwich ELISA -

1. Binding of insulin molecules to the wells of a multi-well plate by a pre-titered amount of monoclonal mouse anti-rat antibodies, and bindin of biotinylated polyclonal antibodies to the captured insulin molecules.

2. Unbound materials are washed away.

3. Binding of horseradish peroxidase to the bound biotinylated polyclonal antibodies.

4. Unbound materials are washed away.

5. The antibody-enzyme conjugates are quantified by monitoring the activities of horseradish peroxidase in the presence of the substrate, 3,3',5,5'-tetramethylbenzidine.

6. The enzyme activity will be measured spectrophotometrically at 450nm. An increase concentration of insulin will lead to an increase formation of the blue color.



The more insulin molecules captured by the antibodies, the higher the absorbance.
Thus an increase in absorbance is directly proportional to the amount of captured insulin.

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Message from Mr. Poh:
Poster format -
1. Go to MS Powerpoint
2. Under "Page Setup", key in the height and width of A1 size
Height: 33.07"
Width: 23.38"
3. Type everything that is to be in the poster on just this ONE slide.

Price for printing A1 size poster in the school : $18. *faints*

That's all!
Charmaine Tan
TG01

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