SANDWICH ELISA EXPLAINED IN 1 MINUTE

ELISA is an abbreviation of enzyme linked immunosorbent assay and utilize the bond between an antibody and its specific antigen for it to work. There are 4 main types of ELISA:
1. Direct ELISA
2. Indirect ELISA
3. Sandwich ELISA
4. Competitive ELISA
Today we will look closer at sandwich ELISA which is carried out in the following manner:
1. First, capture antibodies specific for the target analyte are bound to the floor of a micro well plate.
2. Second, the sample is added and any antigens, present in the sample, that are specific to the capture antibodies bind to them. Then the well is washed to remove all unbound sample components.
3. Third, enzyme-conjugated antibodies which are also specific to the target analyte are added which bind to the antigens on the target analyte.
4. Finally, substrate for the enzyme which is linked to the second antibody is added and the enzyme converts this substrate into an observable signal.
This means that if the target antigen is present, it gets bound by the capture antibody. Then the enzyme-conjugated antibody can bind to the target analyte yet again and in its turn produce a signal once the substrate is added, producing a positive test result. If the target antigen is not present however, this prevents the enzyme-conjugated antibody from binding to them which in turn produces a negative test result.
In other words, if a color change occurs, it is interpreted as a positive test result and if no color change occurs it is interpreted as a negative test result.

[@lovewilltearusapart2792]

Thank you so much! Last minute lifesaver!

[@biotechlucas4126]

Love it when that happens!👍

[@emmahi8909]

Good explanation and visuals, this really helped me understand. Thank you! :D

[@biotechlucas4126]

Great that I could be of help!😇

[@susanmurray9624]

This is great, but your antibodies are binding antigen by the Fc, not the Fab! I would love to show this in my immunology class, but I'm afraid this serious error will confuse their understanding of how antibodies bind.

[@biotechlucas4126]

Yes, you're absolutely right! I got that mixed up when making the video! I apologize and I do plan to make a corrected version. When I do I'll link it to you!👍

[@Mike-fs8ci]

Thanks for your explanation，really helped me， Great job!

[@biotechlucas4126]

Happy to hear that!👍

[@pradyumnakulkarni8411]

thanks for easy and short exaplaination

[@biotechlucas4126]

I am grateful that I could be of service!

[@marielblumelatorre9144]

I just found your channel… nice job!!!

[@biotechlucas4126]

I'm happy you like it😇🙏

[@sofanitsofanitsoliana07]

So perfect

[@biotechlucas4126]

Hahah, I don't know about that but I'm happy you found it useful! Thank you!

[@RedHeadSH0T]

Why in your videos the antibodies are connected to the antigen in their heavy chain region? The attachment to the antigen happens on the opposite side of the antibody, in its Fab region composed of both the light chain and heavy chain.

[@biotechlucas4126]

My apologies! This was a mistake on my part when making the video series on antibodies. I plan on making a correction series in the near future and then deleting these.

[@bat7002]

Thank you 🙏

[@biotechlucas4126]

Happy I could help!

[@adnan.q.753]

Nicely explained

[@biotechlucas4126]

Thank you!