VLD 421: Veterinary Clinical Biochemistry and Laboratory Diagnosis-II (0+1)

INTRODUCTION - ELISA

• Enzyme linked immunosorbent assay, also called ELISA, enzyme immnoassay or EIA, is a biochemical technique used mainly in immunology to detect the presence of an antibody or an antigen in a sample.
• It is a primary binding test.It involves tests using antibodies as reagents.
• Enzyme immunoassays make use of enzymes attached to one of the reactants in an immunoassay to allow quantification through the development of color after addition of suitable substrate / chromogen.

Advantages of ELISA

• Simplicity
  
  • Reagents added in small volume.
  • Separation of bound and free reactants is made easy by simple washing  procedures.
  • Adsorption of protein to plastics is easy
  • Specialized equipment are readily available
• Reading the result
  
  • Coloured end product can be read by naked eye
  • Easily quantify the products by Multichannel spectrophotometers
• Rapidity
  
  • Tests can be performed in a few hours
  • Spectrophotometric reading of results is rapid (96 wells in 5 seconds)
• Sensitivity
  
  • Detection levels of 0.01 to 1 µg/ml are easily and consistently    achievable.
• Adaptability
  
  • Different configurations allow different method to be examined to solve the problems.
• Reagents
  
  • Readily available, safe, non mutagenic, Disposable of waste poses no    problem
• Cost
  • Equipment cost, Reagent cost are low
• Availability
  
  • ELISA can be performed at anywhere, even in laboratories where facilities are very low.