Serologic Techniques Flashcards
Explain serologic procedures
detects ag-ab reactions in vitro
Describe ag-ab reaction
highly specific / “lock and key”,
precise and invisible,
reversible,
contains noncovalent bonds.
two parts of antigen
carrier and hapten
describe hapten
called “determinant”
contains epitope where ab attaches
describe epitope
located in the hapten of an antigen.
paratope of ab attaches to epitope of antigen.
two parts of antibody
arms and stems
describe paratope
found in the Ag binding fragment “Fab” of the antibody. paratope attaches to the epitope of the antigen.
give examples of cross-reactions
cowpox and small pox.
Weil-Felix test - detects rikketsial antibodies using proteus antigens.
*there are similarities in glucolipid antigens
demonstrate Law of Mass Action
Ag+Ab=Ag-Ab
List Intermolecular Forces
Ionic/Electrostatic, Hydrogen, Van der waals, hydrophobic
describe valence
number of combining sites
differentiate affinity from avidity
affinitiy - single, monovalent.
avidity - several, multivalent
describe primary ag-ab rxn
rapid, invisible, not dependent on electrolytes
eg. Immunofluorescence assay (IFA), Enzyme immunoassay (EIA), Radioimmunoassay (RIA).
describe secondary ag-ab reaction
presence of lattice framework.
eg. agglutination, precipitation, complement fixation, neutralization (ASO antibody)
describe tertiary ag-ab reaction
“biologic effects”.
measures complement products, phagocytic index, chemotaxis, inflammation, deposition of immune complexes
describe immuneassays
quick and accurate.
uses antibodies.
detects antigens or “analyte”
other name for Labelled Immunoassay
“Receptor Ligand Assay”
describe Labelled Immunoassay
employs indicator labels.
detects ag/ab.
recommended in low concentration / low-size molecules
types of labelled immunoassay
heterogeneous - mix and read; no separation or washing steps.
homogeneous - needs separation method
Components of Labelled Immunoassay
- Analyte - “ligand”, labelled or unlabeled
- Receptor molecule - “antibody”
- Standards and Calibrators - similar to analyte
- Means of separation of free from bound components
- Means to measure the labelled product - “Reporter molecule”
