1. Serological tests involved in identification of infectious agents Prof M.I.N. Matee

6. Precipitation Tests Lattice Formation

7. PRECIPITATION

9. Precipitation reactions in fluids (p. 142) Precipitation reaction can be seen

14. Agglutination Tests Lattice Formation

19. Hemagglutination Used to identify blood group antigens or antibodies to them Variations: Chemically couple haptens to RBC Use other particles - bacteria, antigen-coated latex beads

20. Agglutination Inhibition Assay for HCG

27. Immunofluorescence Antibodies can be labeled with fluorescent dye Can localize binding sites on cells Dyes: Fluorescein, rhodamine, phycoerythrin can be conjugated to Fc region of Ab (so antigen binding is unaffected) Absorb at one wavelength and emit at another

30. ELISA- enzyme-linked immunosorbent assay Based on RIA Nearly as sensitive Cheaper and safer Many detection systems have been developed Many variations of the assay have been developed

31. All ELISAs use an antibody conjugated with an enzyme that turns a colorless substrate into a colored product Direct- detects antigens using a single labeled antibody against that antigen Relatively few applications and permutations

32. ELI SA Enzyme- L inked I mmunosorbent A ssay (ELISA) © 1998 Gold Standard Multimedia Inc. 1. Antigen HIV Protein 2. Test antibody Human serum 3. Developing Ab Enzyme-Goat anti-Human IgG 4. Substrate Colorless > Blue

33. E nzyme- L inked I mmunosorbent A ssay (ELISA) HIV Ag Human Serum AP-Goat Anti- Human IgG Colorless > Yellow AP = alkaline phosphatase

36. Western Blot for HIV Antibodies + - Patient sera

38. Tests for Cell Associated Antigens Lattice formation not required

41. Radioimmuoassays (RIA) Enzyme-Linked Immunosorbent Assays (ELISA) Lattice formation not required

45. Tissue Immunofluorescence/Immunohistochemistry

47. NEUTRALIZATION

51. CD4 CD8