Immunology- Immunoassay testing

Immunologic tests

• Detect specific infectious agents

• many are in kit form

Color tops

• red top for serum’

• lavender top for plasma unless noted otherwise

Whole blood should not be sent to diagnostic lab

Handling serum

• clot for 20-30 mins at room temp then centrifuge at 1500 rpm

Handling plasma

• centrifuge immediately after collection

pipetting plasma or serum into a transfer tube and label?

• freeze or refrigerate for later use

ELISA

Humoral immunity test

1. most common in vet med

2. most accurate way to detect specific antigens (viruses, bacteria, parasites, hormones)

3. Test for antibodies in serum (test kit contains a specific antigen, tests for heartowrm, feline leukmia, FIV, parvo, and pregesterone heartwormleukemia)

4. critical step is washing away unbound enzymes

CELISA

• equine infectious anemia

• uses patient antigen

• intensity of color varies with concentration

Latex agglutination

• small spherical latex particles coated with an antigen suspended in water

• if serum containing the correct antibody is added, agglutination occurs

• tests for bovine brucellosis

Lateral flow immunoassay

• aka rapid immunomigration or immunochromatography

• positive results show two areas of color, test and control

• uses collodial gold, enzymes, and color reagents or agglutinated latex particles

Looks like a simple small pregnancy test

Immunology analyzers

• available for practices but not common

• larger units used in reference labs