S15: Serology Flashcards
What is serology?
The study into the nature and behaviour of serum antibodies
What is the lock and key relationship?
It means that any given antibody will only react with the antigen that caused its formation in the first place
What is a titration and how does it work?
Determines how much antibody is present in a serum sample. It involves the dilution of a serum sample until no antibody remains.
What is a titre?
The highest dilution at which there is a visible reaction
What are the three agglutination reactions involving bacterial antigens?
- Tube Agglutination
- Rapid Slide Agglutination
- Brucella Milk Ring Test
Describe Tube Agglutination
A reaction where agglutination takes place in a series of test tubes, demonstrated by setting up a series of antibody dilutions and adding a standard amount of antigen to each.
Describe Rapid Slide Agglutination
A simpler test done by dropping a drop of serum (containing antibodies) and a bacterial colony (antigen) on a glass slide, which is then mixed with a tooth pick and observed for reaction (agglutination). Quick, but not accurate
Describe Brucella Milk Ring Test
Designed to detect Brucella antibody in milk. Brucella stained antigen is added to milk sample, then incubated. A blue ring (positive) in the cream layer indicates the milk contains Brucella antibodies
Describe the Gel diffusion precipitate test
Carried out on a nutrient agar. Wells are cut into the agar and antigen and antibodies are put alternate wells, where they will then diffuse out. A fine line of precipitate will form where an antigen meets its particular antibody
How can the many species of Salmonella be differentiated?
Through serotyping by identifying them per differences in the somatic (O) antigen. Antibody to O antigen is produced by injecting somatic antigen into an experimental animal. The serum from this animal will precipitate when mixed with a Salmonella spp. that carries this antigen
What does the Fluorescent antibody test detect?
Antigen in tissue
How does the Fluorescent antibody test work?
Makes use of a labeled antibody. A specific antibody is linked (tagged) to a label (fluorescein isothiocyanate) that fluoresces with ultraviolet light.
What is a common name for EIA?
Swamp Fever
How is EIA tested for?
By the Coggins Test (a gel diffusion test). Blood serum from a horse is placed in a well and an antigen consisting of EIA virus particles is placed in an adjacent well. If a line of precipitate forms, the horse is positive for EIA
What is the difference between direct and viral hemagglutination?
Direct is caused by the antibody, either an isoantibody or a hemagglutinin.
Viral happens when some viruses have the ability to combine on the surface of RBCs, causing the cells to stick together.
