Immunodiagnostic Tests Flashcards
1
Q
Direct Fluorescent Antibody (DFA) Test
A
- detects antigen
- detect Bovine viral diarrhea virus (BVDV) in bovine blood
- detects rabies virus in the brain of the rabid animal
2
Q
Indirect Fluorescent Antibody (DFA) Test
A
- detects antibody
- detects antibody against porcine reproductive and respiratory virus (PRRSV) in swine serum
- positive indirect FAs for antibody to dengue, ChikV, and Zika virus antigens
3
Q
Enzyme Linked Immunosorbent Assays (ELISA)
A
- can either detect antibody or antigen
1. ELISA detecting Antigen - Direct ELISA, Antigen ELISA, Capture ELISA, or Sandwich ELISA
2. ELISA detecting Antibody - Indirect ELISA, or Antibody Elisa
- epitope blocking ELISA, or competitive ELISA
4
Q
Indirect ELISA/Antibody ELISA
A
- wells of ELISA plate are first coated with antigen
- patients serum with Ab is added to wells and incubated
- wash of all unbound antibody
- add secondary Ab to detect if any Ab bound to Ag on the plate
- wash
- > if positive secondary Ab will bind patients Ab
- add substrate for the enzyme and look for color change
5
Q
Direct ELISA/Sandwich ELISA/Antigen Capture ELISA
A
- wells of ELISA plate are first coated with antibody (capture Ab)
- sample is added to well
- of sample contains antigen that is recognized by Ab, will bind and stick to plate
- wash of all unbound antibody
- add Ab specific for the antigen you are testing for (detection Ab)
- wash off all unbound second Ab
- only detection Ab will be tagged with an enzyme
- add substrate to the enzyme bound to the second Ab and look for color change
6
Q
Competitive ELISA/Epitope Blocking ELISA
A
- detection of Ab is made to the antigen/epitope of interest
- do not need anti-species antibody, can run serum from any species
7
Q
Western Blot
A
- identify specific proteins in a complex protein mixture OR to see if patient’s serum contains antibody specific proteins
- first step is gel electrophoresis
- Separated molecules are transferred/blotted onto immobilizing paper (nitrocellulose membrane)
