EXAM 15: serology Flashcards
you can identify an unknown reagent using
a known antigen or antibody
serology
- the study into the nature and behavior of serum antibodies
- an important feature is the lock and key relationship
titration
- a procedure used to determine how much antibody is present in a serum sample
- is the greatest dilution of antibody that will still cause a visible reaction
- agglutination or precipitation indicates an antibody/antigen reaction
- the highest dilution that has a reaction is called a titer
agglutination
- clumping of the antigen in the presence of the specific antibody
- antigens that do this are small particles that stick together when they come in contact with a specific antibody
what are the types of agglutination reactions
- tube agglutination
- rapid slide agglutination
- brucella milk ring test
precipitation reactions
- antigen molecules are much smaller
- the antigen is part of the solution and becomes visible only after it has reacted with an antibody
- product is a fine precipitate
- commonly used to detect viral antibodies (therefore can be used to help diagnose disease)
Gel diffusion
- a precipitation reaction
- The test is done in a petri dish
- wells are cut into the agar, and the antigens and antibodies are put into it. They diffuse into the agar and where they meet there will be a fine line of precipitate
- can be used to detect viral disease
serotyping
differentiating based on cell surface differences
fluorescent antibody
are reactions that make use of a labeled antibody
- used to detect the rabies virus
Coggins test
- gell diffusion test
- designed to detect antibodies for equine infectious anemia (EIA)
- will detect the antibodies within 45 days
- very serious and all horses must be tested
What is commonly called ‘swamp fever’
equine infectious anemia
hemagglutination
the clumping or sticking together of RBC
direct hemagglutination
- caused by antibody
- can be an isoantibody (natural) or a hemagglutinin (antibody produced in experimental animals)
viral hemagglutination
some viruses which have the ability to combine on the surface of RBC cause these cells to stick together
viral hemagglutination inhibition test
- utilizes specific antibodies to neutralize the virus and inhibit the reaction
- has diagnostic value, it can reliably tell the vet if a certain antibody is present in an animal
complement
- protective factors that are part of the immune system
- may be necessary for some antibody/antigen reaction
is why the following happens:
1. antigen + fresh serum = living
2. antigen + serum that has been heated = death
3. antigen + aged serum = death
4. antigen + heated serum + fresh serum = live guinea pig
is described as a helper
characteristics of complement
- causes lysis of sensitive bacterial cells ]
- combines with numerous antigen/antibody complexes to become fixed and is then unavailable to react with other antigens or antibodies
- stimulates WBC to aid the destruction of bacteria
- aids in the destruction of certain viruses
- inactive at 56 Celsius after 30min (fragile nature)
- inactivated by sitting at room temperature for a few hours
- is broken down by heat
- is naturally present in the serum of healthy animals
- e.g: Q fever, brucella, syphilis
