ELISA tests

• can be used to test for the presence of any antigen or antibody
• • an antibody is bound to an enzyme
  • the enzyme reacts with a substrate to produce colour change
  • the antibody will be complimentary and bind to the antigen or an antibody the test is designed to detect
  • the washing step with remove any unbound antibodies
• indirect - uses multiple antibodies

  • antigens are immobilised and the sample being checked for antibodies is added
  • a wash step occurs before a second antibody is added which will bind to the antibodies attached to the antigens if present
  • the antibody has the enzyme bound that will change colour
• indirect ELISAs can be more sensitive that direct detection methods