Immunodiagnostics (36) Flashcards
Dr. Phillips
Why immunodiagnostics?
quality of immune response can be assayed
functioning appropriately
causing disease like auto-immunity
can be used to determine specific amounts of components
other assays for infectious disease and neoplasms typically involve the binding of antigen to antibody
What is the most common immunologic assay used in practice?
flow cytometry
Assays are also available to determine function of ______
different cell types: lymphocyte function, neutrophil function, platelet function, macrophage function
What is flow cytometry used for?
used to determine the relative number (%) of a particular type of cell in a sample
What does flow cytometry differentiate cells based on?
interaction with light
electrical conductivity
antibody binding
What are the components of flow cytometry?
sheath or flow cell
measuring system
detector amplifier
computer for analysis
What is forward scatter - flow cytometry?
cells are identified based on size as rbcs, lymphocytes, monocytes, granulocytes
What is side scatter - flow cytometry?
cells are identified based on complexity as rbcs, lymphocytes, monocytes, granulocytes
Side scatter sorts cells based on _____ and forward sorts based on ______
side: cellular complexity
forward: size
What is fluorescence intensity via flow cytometry?
cells are tagged with antibodies (T and B); fluorescent light tags and lights them up
differentiate subpopulations like CD4+
[Granulocytes/Lymphocytes] are more complex and thus are higher on the flow cytometry graph
granulocytes
In flow cytometry, two antibodies may used at the same time - labeled with different fluorescent tags. What are they called?
anti-CD8
anti-CD4
Anti-CD8 is coupled to _____ and anti-CD4 is coupled to
phycoerythrin
fluorescin
What are some common flow markers?
antibodies to target multiple epitopes
Which surface marker is helpful for diagnosing retroviruses like FeLV and FIV?
CD4
in these viruses, there is a deficiency of CD4
What do lymphocyte function assays require?
isolation or cultivation of the patient’s lymphocytes
What are proliferation assays?
stimulation of lymphocytes with mitogens/antigens
What is the neutrophil function assay?
tests ability of neutrophil to phagocytose cells
If a neutrophil function assay is normal, it will turn a _____. If abnormal, it will
turn a blue-black color (meaning is phagocytosed)
abnormal: will not
What is the Coomb’s test?
involves mixing the Coomb’s reagent (antiserum IgG, IgM, and C3) with patient red blood cells
positive patient: is clumped with antibodies
What is radial immunodiffusion?
antigen/antibody detection
used to quantitate both total protein level and pathogen-specific Ig
What does radial immunodiffusion rely on?
zone of equivalence
optimal antibody/antigen binding occurs here
excess antibody/antigen: results in low immune complex formation
What is serum protein electrophoresis?
assay to measure multiple proteins spontaneously
