3 types of Unlabeled Immunoassays - ANSPrecipitation
Agglutination
Electrophoresis
Precipitation involves combining __1__ with __2__ to produce insoluble complexes that are
visible - ANS1) soluble antigen
2) soluble antibody
Agglutination is a process by which __1__ (bacterial cells, RBCs, etc.) aggregate to form larger
complexes when a specific __2__ is present. Antibody can also be __3__ if linked to __4__ -
ANS1) particulate Ag
2) Ab
3) particulate
4) latex beads
Affinity - ANSStrength of binding of one Fab with one epitope on an antigen
(Strength of binding between a single antigenic determinant and an individual antibody)
The higher the __1__, the more __2__ the reaction because of what? - ANS1) affinity
2) sensitive
Because less of the antigen will be in the uncompleted form
Avidity - ANSMeasure of the overall strength of binding of an antigen with many antigenic
determinants and multivalent antibodies
(Binding is often with multiple epitopes to multiple antibodies = the total strength or avidity)
Why are precipitation reactions the least sensitive serologic methodologies? - ANSIt requires
high concentrations of antigen and antibodies for detection
3 zones of a precipitin curve - ANSProzone
Equivalence
Postzone
Zone of Equivalence: affect on the amount of precipitation - ANSAg and Ab meet at a
concentration where the number of antibody binding sites (paratopes) approximately equals the
number of epitopes (Ag and Ab molecules are at an optimal ratio)
Prozone: affect on the amount of precipitation - ANSLittle or no precipitate would form making it
seem like the patient didn't have antibody to the antigen.
Antibody-excess zone
, Postzone: affect on the amount of precipitation - ANSPatient Ab is low thus little or no
precipitation occurs
Antigen-excess zone
Nephalometry (3) - ANSInsoluble lattice complexes diffract light.
Detector is usually placed at a 70-90° angle from the light source.
As concentration of the analyte increases so does the cloudiness
Turbidometry (3) - ANSInsoluble lattice complexes block transmitted light.
Detector is placed in line with the light source
As concentration of the analyze increases so does the cloudiness
3 things in common for both Nephalometry and Turbidometry - ANSVery quantitative
Not sensitive
Must measure high concentration analytes
Nephelometry best at measuring what? - ANSBest at measuring very fine precipitates
Soluble antibody/antigen
Turbidometry best at measuring what? - ANSBest at measuring larger precipitates/small
aggregates
Can be used with small latex bead reagents
Immunodiffusion theory (3) - ANSAg and Ab are placed in wells
Diffusion occurs at a constant rate outward
Concentration near center of application but as it diffuses the concentration decreases
Ouchterlony is a ____ immunodiffusion gel precipitation. - ANSdouble-diffusion
Radial immunodiffusion (RIA) is a ____ immunodiffusion gel precipitation - ANSsingle-diffusion
Ouchterlony 2 uses: - ANSTest if an antibody response developed
Antigenic relationship between two antigens can be analyzed
Ouchterlony is a __1__ procedure to identify __2__ against __3__. - ANS1) qualitative
2) antibodies
3) infectious agents
Ouchterlony allows determination of whether the unknown is __1__, __2__, or __3__.
Ouchterlony can also be used to detect __4__ infections - ANS1) identical
2) partially identical
3) nonidentical with the known Ag
4) fungal
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller QualityPDF. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.49. You're not tied to anything after your purchase.