Enzyme Immunoassays Overview

True (A)

Homogeneous enzyme immunoassays are simpler and faster, requiring no washing steps.

<p>antibody</p> Signup and view all the answers

<p>Heterogeneous enzyme immunoassays = Involve washing and separation steps Homogeneous enzyme immunoassays = Do not require washing or separation steps Sandwich immunoassay = Uses capture antibodies to bind the antigen Immunochromatography = Combines all steps into one Capture assays = Bind antigens to a solid phase Rapid immunoassays = Membrane-based and easy to perform</p> Signup and view all the answers

<p>Catalase (C)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>spectroscopy</p> Signup and view all the answers

<p>antibody</p> Signup and view all the answers

<p>Requires specialized, expensive equipment for measurement (D)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Competitive EIA = Enzyme-labeled antigen competes with unlabeled patient antigen for binding sites Non-competitive EIA = Enzyme-labeled reagent binds after the initial antigen-antibody reaction Direct EIA = Enzyme-labeled antibody directly binds to antigen Indirect EIA = Enzyme-labeled secondary antibody binds to primary antibody bound to antigen</p> Signup and view all the answers

<p>analyte</p> Signup and view all the answers

<p>To maintain a constant capillary flow rate (D)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Fluorescent labeling allows for the visualization of antibody-antigen interactions under a fluorescent microscope.</p> Signup and view all the answers

<p>Fluorescein = Green Tetramethylrhodamine = Red</p> Signup and view all the answers

<p>To indirectly measure the concentration of a target antigen by using a labeled reactant (C)</p> Signup and view all the answers

<p>Emits blue light (D)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Heterogeneous and Homogeneous</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>antibody</p> Signup and view all the answers

<p>capture antibody</p> Signup and view all the answers

<p>Radioactive isotope (A)</p> Signup and view all the answers

<p>Competitive immunoassays = All reactants are mixed simultaneously, labeled antigen competes for binding sites with patient antigen, the amount of bound label is inversely proportional to the concentration of patient antigen. Non-competitive immunoassays = Capture antibody is absorbed onto a solid phase, patient antigen binds to capture antibody, labeled antibody binds to captured patient antigen, the amount of bound label is directly proportional to the concentration of patient antigen. Heterogeneous immunoassays = Require a separation step to remove free analyte from the bound analyte. Homogeneous immunoassays = Do not require a separation step.</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>The labeled reactant competes with the patient antigen for binding sites on the antibody. The amount of bound label is inversely proportional to the concentration of the patient antigen.</p> Signup and view all the answers

<p>It is more sensitive and can detect smaller amounts of antigen. (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>Fluorescence Polarization Immunoassay (FPIA)</p> Signup and view all the answers

<p>labeled, unlabeled</p> Signup and view all the answers

<p>Direct Immunofluorescence = Detecting Legionella pneumophila in a sample Indirect Immunofluorescence = Measuring antibody levels in patient serum Fluorescence Polarization Immunoassay (FPIA) = Quantifying the concentration of a specific antigen in a sample</p> Signup and view all the answers

<p>In indirect immunofluorescence, the patient's serum is incubated with a known antigen on a slide. Then, an anti-human immunoglobulin labeled with a fluorescent tag is added. This antibody binds to the patient's antibodies attached to the antigen. The fluorescence is localized, indicating the presence of the specific antibody in the patient's serum.</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>Indirect Immunofluorescence (A)</p> Signup and view all the answers

An assay where labeled antigen competes with unlabeled patient antigen for binding sites.

An assay where a capture antibody is fixed to a solid phase to capture patient antigen.

Non-competitive immunoassays are more sensitive than competitive ones.

Assays that do not require a separation step between bound and free reactants.

Assays that require a physical step to separate bound from free analytes.

The first developed immunoassay using a radioactive label to detect substances.

In immunoassays, the label must remain stable throughout the shelf life.

Useful for measuring hormones, vitamins, and serum proteins.

An antibody bound to a solid substrate in assays.

The step where a substrate is added to measure enzyme activity corresponding to antibody presence.

Assay where antibodies capture antigens, often called sandwich immunoassays.

Features of antigens recognized by different antibodies within capture assays.

The amount of color, fluorescence, or luminescence measures antigen quantity in the sample.

Rapid assays without wash steps, used for detecting low-molecular-weight analytes.

Membrane-based tests designed for point-of-care or home settings, providing quick results.

A type of rapid assay combining multiple test steps into one for simplified testing.

A radioactive label commonly used in immunoassays.

Enzymes react with substrates to produce measurable breakdown products.

Breakdown products from enzymes can be chromogenic, fluorogenic, or luminescent.

Commonly used enzyme in immunoassays, it produces measurable results.

An enzyme immunoassay where labeled antigens compete with unlabeled ones for binding sites.

An immunoassay where the enzyme-labeled reagent binds after initial binding has occurred.

A type of non-competitive EIA where the reagent binds only after antigen-antibody reactions.

In non-competitive EIA, antigens are attached to a solid phase like microtiter plates.

The substance being tested on a diagnostic strip.

The area on the strip where immune complexes are captured and detected.

The structure formed when an antigen binds to an antibody.

Molecules that fluoresce when exposed to light.

A fluorophore that emits green light, used for labeling antibodies.

A fluorophore emitting red light, commonly used in immunofluorescence.

A test utilizing fluorescent labels on antibodies to locate antigens.

A method where labeled antibodies directly bind to antigens in tissues.

A specialized microscope that detects fluorescence in samples.

Antigens seen as bright apple green or orange-yellow under a fluorescence microscope.

A technique based on changes in light polarization when antigens bind to antibodies.

Labeled antigens compete with unlabeled antigens for antibody-binding sites in FPIA.

In FPIA, outcoming polarization is inversely related to the analyte concentration.

In indirect immunofluorescence, the fluorescent anti-human antibody binds to the primary antibody.