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PHM142 Fall 2019 Instructor : Chesa Dojo Soeandy Coordinator: Jeffrey Henderson. E.L.I.S.A. PRESENTERS : MINRONG (ERIN) LI, SEUNG BEOM (JASON) BONG, CARMEN LIN, CHRISTINE TAN. CONTENTS. What is ELISA? How ELISA Works Direct and Indirect Capture Competitive and Sandwich Capture
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PHM142 Fall 2019 Instructor: Chesa Dojo Soeandy • Coordinator: Jeffrey Henderson E.L.I.S.A PRESENTERS: MINRONG (ERIN) LI, SEUNG BEOM (JASON) BONG, CARMEN LIN, CHRISTINE TAN
CONTENTS • What is ELISA? • How ELISA Works • Direct and Indirect Capture • Competitive and Sandwich Capture • Applications of ELISA • Summary
[1] DISCOVERY
What is ELISA? [1] • Diagnostic immunoassay • Commercially successful starting 1970s • Fully automatic systems starting 1980s • Laboratory technique staple Promotional photo of first EIA
Demonstration of general ELISA concept DEMONSTRATION
How ELISA Works • Specific binding of antibody to specific ligand • General Method • Immobilization of Antigen • Detection Antibody • Label [2]
Direct and Indirect Capture • Direct • Antigen directly attaches to wall by passive adsorption • Detection antibody attaches to antigen directly • Indirect • Antigen adsorbed to wall and antigen-specific antibody attaches to antigen directly • Separate Detection antibody attaches to antigen-specific antibody [2]
Competitive Capture • Measures the concentration of an antigen in a sample by detecting interference in an expected signal output • Used when the antigen is small and has only one antibody binding site [3]
Sandwich Capture • Most specific form of ELISA • The antigen is bound between a layer of capture antibodies and a layer of detection antibodies • Each antibody is specific for a different antibody binding site on the antigen • The capture antibody may be conjugated or unconjugated • Conjugated - Direct ELISA • Unconjugated - Indirect ELISA
Advantages vs. Disadvantages ELISA Advantages Direct Indirect Competitive Sandwich • Fast • Less error • Efficient • Sensitive • Fast • Highly specific • Antigen does not require purification prior to use • Impure samples may be used • High reproducibility • Inspecific • No signal amplification • Extra step • Cross-reactive • Antigen must contain at least 2 antibody binding sites • Lower sensitivity and specificity Disadvantages
Applications of ELISA • Food Allergens • Cancer Screening • Detecting Viruses • Others
Application of ELISA: 1. Food Allergens • ELISA is commonly used in the food industry to ensure safety • Detects the presence of allergens • Advantageous over other methods when testing for: • Oils, egg whites, and milk • Can detect at concentrations on the low parts per million (ppm) scale [4] Common food allergens.
Application of ELISA: 2. Cancer Screening • ELISA can detect tumor markers are synthesized by tumor cells • Tumor markers may be used to: • Detect early stages of cancer • Monitor response to treatment • Look at the initial level of tumour marker and compare it with the current level • Determine whether the cancer has recurred after treatment [5] Microscopic tumor cell.
Application of ELISA: 3. Detecting Viruses • Viruses invade and colonize host tissues and induce the host to generate antibodies • ELISA can detect and measure these antibodies • ELISA has been used to detect: • HIV • West Nile virus • Newcastle disease virus (NDV) • Viral infection rates are high in developing countries • Instant results at testing locations [6] Microscopic HIV.
4. Other Applications of ELISA • Veterinary • Plant pathogen • Pesticides • Autoimmune disease • Gastrointestinal disease • Many more!
SUMMARY • Enzyme-linked immunosorbent assay (ELISA) is a staple laboratory technique today • Relies on specific binding of antibody to antigen • General Method • Immobilization • Detection • Label • There are 4 different types of ELISA techniques: • Direct • Indirect • Competitive - Highly reproducible • Sandwich - Highly specific • Some applications of ELISA are: • Food allergens • Cancer screening • Detecting viruses
Works Cited Barnett, C. (2019, June 20). ELISA Applications. Retrieved from https://www.news-medical.net/life-sciences/ELISA-Applications.aspx Bio-Rad. (n.d.). Retrieved from https://www.bio-rad-antibodies.com/blog/deciding-which-elisa-technique-is-right-for-you.html Creative Diagnostics. (2009). Products. Retrieved from https://www.creative-diagnostics.com/ELISA-Kits.htm ThermoFisher. (n.d.). Overview of ELISA. Retrieved from https://www.thermofisher.com/ca/en/home/life-science/protein-biology/protein-biology-learning-center/protein-biology-resource-library/pierce-protein-methods/overview-elisa.html Images: • Lequin, R. M. (2005). Enzyme immunoassay (EIA)/enzyme-linked immunosorbent assay (ELISA). Clinical chemistry, 51(12), 2415-2418. • ELISA. Retrieved from https://www.sbhsciences.com/ELISA.asp. Konstantinou G.N. (2017) Enzyme-Linked Immunosorbent Assay (ELISA). In: Lin J., Alcocer M. (eds) Food Allergens. Methods in Molecular Biology, vol 1592. Humana Press, New York, NY. • ELISA- Principle, Types and Applications. (2015, July 28). Retrieved from http://microbiologynotes.com/elisa-principle-types-and-applications/ • Flucke, J. (2018). University of Michigan Discovers Vaccine Suppresses Peanut Allergy in Mice . Retrieved from http://blog.denticle.com/2018/04/university-of-michigan-discovers.html • Creative Diagnostics (CD). (n.d.). Microscopic tumor. Retrieved from https://www.creative-diagnostics.com/tumor-marker.htm • Radowitz, J. von. (2015). Hiv under the microscope. Retrieved from https://www.mirror.co.uk/news/technology-science/science/hiv-vaccine-trials-to-begin-6752566
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