Lab Analysis of the Immune Response - MMG201 Chapter 20

Vocabulary terms and definitions covering Chapter 20: Lab Analysis of the Immune Response, including various immunological assays and diagnostic methods.

Epitopes

Also known as antigenic determinants, these are the specific regions on an antigen where antibodies bind.

Precipitation reaction

An in vitro assay where large complexes called lattices form and settle out of solution when both antibodies and corresponding antigens are present.

Monoclonal antibody serum

A serum containing antibodies that bind to a single specific epitope.

Polyclonal antibody serum

A serum containing antibodies that bind to many different epitopes.

Qualitative assay

An assay that determines the presence or absence of a substance but cannot measure its concentration.

Quantitative assay

An assay that measures the specific concentration of either an antigen or an antibody in a sample.

Precipitin Ring Test

A qualitative simple diagnostic test where precipitation happens in the middle of a tube (prevented from mixing by glycerol) to show the relative amount of antibody in antiserum.

Ouchterlony Test

A qualitative double immunodiffusion assay where antigens and antisera diffuse through agar to form a visible arc at the zone of equivalence.

Radial Immunodiffusion (RID)

A quantitative assay where precipitation forms a ring around an antigen/antibody well in agar, allowing for the measurement of the concentration of serum proteins.

Flocculation

A qualitative assay similar to precipitation, but specifically for insoluble antigens such as lipids, where antibodies form visible aggregates with the suspension.

VDRL (Venereal Disease Research Lab) Test

An indirect flocculation method used to detect antibodies to treponemal antigens associated with Syphilis (Treponema pallidum).

Neutralization Assay

A test where antibodies bind to a virus to block viral entry into target cells, preventing the formation of plaques.

Immunoblot Assay (Western Blot)

A technique that uses enzyme-antibody conjugates to identify specific proteins that have been transferred to an absorbent membrane after immunoelectrophoresis.

Complement fixation test

An immunoassay used to detect antibodies against pathogens difficult to culture, such as fungi or Chlamydia, where antibody binding to antigen induces complement activation and prevents the lysis of red blood cells.

Agglutination

The clumping of cells or particles caused by antibodies binding to them, used to indicate the presence of antibodies against bacteria or viruses, or to determine blood type.

Latex fixation

An indirect agglutination assay where antibodies are attached to inert latex beads to detect the presence of specific antigens or antibodies.

Direct Coombs’ test

A hemagglutination assay used to detect antibodies that are already adhered to the surface of red blood cells.

Indirect Coombs’ test

Also called the indirect antiglobulin test, it is used to identify antibodies floating in the blood, such as when confirming blood transfusion compatibility.

ELISA (Enzyme-linked immunosorbent assay)

An assay using enzyme-antibody conjugates to detect and quantify target molecules through a measurable color change or fluorescence.

Immunohistochemistry (IHC)

A type of immunostaining used for examining whole tissues where antibody-enzyme conjugates bind to specific targets.

Immunocytochemistry (ICC)

An immunostaining technique used for examining specific cell structures where antibodies pass through the cell membrane to bind to internal targets like organelles.

Lateral flow test

An immunochromatographic assay that uses fixed antibodies to capture color-labeled antigen-antibody complexes for quick diagnosis, such as for SARS-CoV-2 or pregnancy.

Direct fluorescent antibody (DFA) test

A technique using fluorescently labeled monoclonal antibodies to bind and illuminate a target antigen, allowing for rapid diagnosis of bacterial diseases like strep throat.