Immunology Lab Exam 1 Assorted Flashcards
Describe the principle of double diffusion.
Antigen is placed in a center well, QC antibody placed on top and bottom wells, and 4 patient serums placed in 4 corner wells. Antigen and antibody both diffuse through the medium and form a precipitate when they meet. If patient antibody matches QC antibody, there will be an identity result at that corner.
2 main types of group A strep infection
streptococcal pharyngitis
streptococcal skin infection
complications of group A strep infection
acute rheumatic fever
glomerulonephritis
acute rheumatic fever happens 20 days after …..
strep throat
acute rheumatic fever cross reaction
Ab binds to myosin of heart muscle
glomerulonephritis happens 10 days after…
either group A strep infection
glomerulonephritis cross reaction
Ab binds to basement membrane of glomerulus
hallmarks of glomerulonephritis
edema and hypertension
5 exoantigens released by strep group A
- streptolysin O
- hyaluronidase
- DNAse B
- NADase
- streptokinase
complications of strep group A infections rely on …. to diagnose
serologies
cannot be cultured at that point
2 strep antibodies most commonly tested for
ASO (anti SLO)
Anti-DNase B
standard method of strep serology
explain principle
units
neutralization assay
SLO reagent added to patient serum. If patient has ASO, it will neutralize the SLO. RBCs are added. If hemolysis occurs, this is a negative. If hemolysis does not occur, this shows that SLO has been neutralized and the patient is positive.
Todd units
more widely used serology methods for strep
- slide agglutination
- nephelometry
- EIA
Anti-DNase B shows up (before/after) ASO in strep pharyngitis.
Before
ASO is not seen in patients with ….., so instead we test for anti-DNase B.
glomerulonephritis preceded by skin infection
