ELISA

1
ELISA

• Hari Kiran Kotapati and Dusty Bratton

2
Overview

• A biochemical technique used to detect antigens
• Sample is washed over with a specific antibody
  linked to an enzyme
• When the antibody binds with the antigen the
  enzyme emits some type of detectable signal

http//www.microvet.arizona.edu/courses/mic419/Too
lBox/elisa3.jpg
3
Types

• Indirect ELISA
• Sandwich ELISA
• Competitive ELISA
• Reverse ELISA

http//newenglandbiolabs.de/en/images/stories/cst_
elisa_gross.jpg
http//media.wiley.com/CurrentProtocols/MB/mb1102/
mb1102-fig-0002-1-full.gif
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Procedure
http//www.elispot-analyzers.de/english/elisa-anim
ation.html
5

• Day 1

• Antigen preparation
• Working peptide antigen concentration is 10
  microgram/ml
• Coating
• -- Humid chamber

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Day 2 (Part 1)

• Blocking
• Serum sample

7
Day 2(Part 2)

• Secondary Antibody
• Development

8
HIV / West Nile
http//media.publicbroadcasting.net/kera/newsroom/
images/3197830.jpg

• ELISA was the first screening tool widely used
  for HIV
• Can determine serum antibody concentrations in
  West Nile
• Some controversy over cut-off point for /-
  test.

http//toxics.usgs.gov/photo_gallery/photos/pestic
ides/AnalyticalMethods/AM_ELISA_Supplies_lg.jpg
http//www.stanford.edu/group/virus/retro/2005gong
ishmail/hiv2.jpg
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Food Allergens
http//nashvillehealthnut.files.wordpress.com/2009
/09/almonds-closeup.jpg

• Used to detect traces of allergens in food
  products

http//kidscientist.com/wp-content/uploads/2007/08
/eggs.jpg
http//www.thenutfactory.com/photos/nuts-peanuts-b
lanched-ns.JPG
http//z.about.com/d/15minutefashion/1/0/I/0/-/-/m
ilk.jpg
http//img.alibaba.com/photo/10761554/Walnuts_Butt
erfly_or_Quarters_Extralight_Light_or_Amber.jpg
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References

• http//www.elispot-analyzers.de/english/elisa-anim
  ation.html
• http//www.mabtech.com/main/Page.asp?PageId26Pag
  eNameAboutELISA
• http//www.prosci-inc.com/ELISA-Protocol.html
• http//www.biology.arizona.edu/immunology/activiti
  es/elisa/main.html
• http//web.archive.org/web/20080325193553/www.cfsa
  n.fda.gov/dms/alrgpart.html

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• 1. ELISA stands for
• a. Enzyme-linked immunosorbent assay
• 2. ELISA is used to test for
• d. All of the above
• What biochemical molecule is the ELISA test
  usually specific for
• d. Proteins
• 4. How long does the sample ELISA protocol
  presented take
• b. 2 days
• True There is some controversy over the
  cut-off point for positive and negative test
  associated with HIV.