Immunodiagnosis Flashcards
What antibody is used to detect B cells?
CD19
What antibodies can used to detect T cells?
Either CD3 or CD4 and CD8
How does a flow cytometer work?
Pump cells single file through an orifice and illuminate them with a laser. The light is collected an analyzed
Can flow cytometers identify cells that are dividing?
Yes with the use of propidium iodide
How can flow cytometry be used to detect cytokies and transcription factors?
If the cells are fixed and permeabilized
How do we normally quantify B cells?
Electrophoresis. Cheap but not sensitive
What test can measure levels of individual immunoglobulin classes or subclasses?
Single radial immunodiffusion.
Fairly cheap but slow
What is the best overall test used to determine T cell function?
Skin test to common antigens
True or False: You can test T cell function by performing a test in which you have lymphocytes+monocytes mixed with T cell mitogens PHA and Con A. This tricks ALL T cells into thinking they see an antigen and they start producing IL-2, IL-4 and INF gamma
True
What can you do to test an infants T cell fucntion
X ray
What would you do to test a patient that you suspect has a primary immunodeficiency?
Lymphoid biopsy
How do you diagnose an autoimmune disease characterized by antinuclear antibodies?
Fix a cell to a slide. Make it permeable so the anitbodies can get into the nucleus. Place the patients serum onto the slide. Add goat-antihuman antibodies that have fluorescent makers. Observe under UV microscope
How do you detect rheumatoid factor?
Bind IgG to latex particles. See if the patients serum (which containis IgM) agglutinates
What test would you do if you suspected your patient had a type III disease?
Take the patients serum and place it in the refrigerator for about 1-7 days.
Immune complexes are less soluble in the cold so you should see some cryoglobulins
What if you are not sure if your patient has Type II or type III immunopathology?
Immunofluoresence should help
What is the main difference between immunofluoresence and immunohistochemisty?
Instead of using an antibody bound to a fluorescent molecule you use an antibody bound to a peroxidase.
You can visualize a brown pigment under a regular microscope
How can we test for specific antibodies?
Simple ELISA
What are two types of immunofluorescence?
Direct and indirect
What is passive agglutination?
You add dilutions of the patients serum to latex beads that are bound to an antibody.
It looks for the agglutination titer
What is a titer?
The reciprocal of the highest dilution that will still do something
What tests can you use if an antigen is divalent?
Sandwich or capture ELISA
What are fluorescent immunoassays?
A substrate that become a fluorescent product
True or False: an antigen with only one epitope can be measured in a capture assay?
False. For antigens with only one epitope you have to use a competition assay
What do rapid screens do?1
They can be used to detect the presents of Streptococcus by passing sample through a membrane that has Strep antigens stuck to it. Kind of like capture actually
Detergent pops liposomes and produces color
Reverse passive agglutination is a process in which timy latex beads are coated with antibodies to bacteria. What is this process used to detect?
Bacterial meningitis
