Transcript ELISA BASICS Enzyme Linked Immunosorbent Assay

ELISA BASICS
Enzyme Linked Immunosorbent
Assay
Food Safety Scientist Curriculum
This project was supported by the USDA NIFA grant number 2011-38411-30625
© 2014 Board of Regents, South Dakota State University
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Introduction of ELISA
 Introduced
by Engvall and Pearlmann in 1971.
 Review
the following
 Basic principles of ELISA
 Advantages of using ELISA
 Uses of ELISA widely used
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Basic Principles of ELISA
Based on Basic Immunology Response
 Lock
and Key Concept
 Antigen (Key): substance when introduced into
the body produces antibodies
 Antibody (lock): protein in the body that is used
by immune system to identify and neutralize
foreign targets (referred to as antigens)
 Key fits into the lock
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Basic Principles Cont’d.
 Enzyme
conjugate substrates
 Enzyme that converts colorless substrates to a
colored product
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Visualization of ELISA
 ELISA
Graphic Animation:
http://www.youtube.com/watch?v=70TPrfL_8M&feature=relmfu
Created by Cary Engleberg of the University of
Michigan
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Advantages of ELISA
1.
Fast – 90 samples tested in 2-3 hr
2.
Sensitivity (up to 10 pg/mL)
3.
Specificity (sample with high concentration contaminants
4.
Many samples can be processed at once
5.
Small sample size required (10μL ~ 100 μL)
6.
Colorimetric results – easily observed and measured
(spectrophotometer)
7.
Test for presence of Ag or Ab
8.
Flexible usage for research design
9.
Easy to learn, simple procedure
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Lateral Flow Tests

Variation of ELISA Test. Paper strips instead of micro test well.

Test strip – paper with antibody and colored beads
preloaded strategic locations.

Test solution flows laterally across paper, eventually reaches
antibodies.

If the antibody and antigen (i.e. an allergen) bind – color
beds are activated.

Often a qualitative test – yes or no at a specific level
YouTube Graphic Animation Lateral Flow Device:
http://www.youtube.com/watch?v=FvIIozN58gw&feature=endscreen&NR=1
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Can you identify specific types of
test kits for the categories below?

Viral Contamination

Drugs

Hormone levels

Allergens in food

Infections

Residues in food

Specific disease factors

Toxins in food

Others
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