VETN 203B — Serology

Serology kits

Have all supplies included, takes minimal time and effort, quality control is vital

Sensitivity

The ability of the test to correctly identify all animals that are truly positive for a given reaction procedures; a large number of false negatives = a low sensitivity

Specificity

A measure of the number of false positives produced with the given reaction procedure

tests of humoral immunity

Enzyme immunoassay, latex agglutination and rapid immunomigration

enzyme-linked immunosorbent assay (ELISA)

Most common type of immunoassay used in the veterinary clinic lab, accurate way to detect specific antigens (viruses, bacteria, parasites, hormones, heartworm, FELV/FIV, parvovirus, progesterone)

monoclonal antibodies

a collection of identical antibodies that interact with a single antigen site

Latex agglutination

antibody binds to the surface of antigen-coated latex beads

What is latex agglutination commonly used for

Bovine brucellosis

Lateral Flow Immunoassay

A sample that contains antigen flows through a porous strip, and positive reactions are shown by the appearance of a colored band

Rapid immunomigration

A simple test which detects specific antigens

Immunochromatography

Very rapid and easy-to-read ELISAs

Antigen solution flows through a porous strip

Encounters labeled antibody

Visible line produced when antigen-antibody immune complexes encounter antibody against them

Used in pregnancy testing and for rapid identification of some infections

Intradermal testing

a diluted allergen is injected ID and the pt is observed. if the wheal becomes inflamed with induration (raised, hard area ) the substance can be identified as an allergen

Allergies

Having a hypersensitivity to a substance that does not normally cause a reaction.

Hypersensitivity reaction

Triggered when basophils or mast cells release histamine-containing granules which triggers an inflammatory response

Tuberculin skin test

a skin test to determine past or present infection with the tuberculosis bacterium

Coombs test

used to detect antibodies that act against the surface of your red blood cells. The presence of these antibodies indicates a condition known as hemolytic anemia, in which your blood does not contain enough red blood cells because they are destroyed prematurely.

Immunodiffusion

an immune test in which antibodies and antigens diffuse from separate wells in agar to form a line of precipitate

What are immunodiffusion tests used for

Equine infectious anemia (coggins) or Johne disease

Fluorescent antibody test

Technique that uses fluorescently labeled antibodies to detect specific antigens on cells attached to a microscope slide

Antibody titers

measures amount of a specific type of antibody present in the patients plasma

a higher titer indicates

Active infection

A lower titer indicates

Previous exposure to an antigen

Molecular Diagnostics

Identify the presence of pathogens (viruses, fungi, bacteria) and is based on the analysis of RNA or DNA

polymerase chain reaction (PCR) test

A diagnostic tool that locates trace amounts of DNA