Deck 5: Immunoassays

Question 1

Which of the following substances does glucose-6-phosphate dehydrogenase bind to in the EMIT assay?

A) Coenzyme
B) Substrate
C) Antigen
D) Antibody

Answer 1

Antigen

Question 2

Which of the following describes the composition of the two particles used in the luminescent oxygen channeling immunoassay (LOCI)?

A) High-energy fluorescent radiation bead and a low-energy fluorescent radiation bead coated with luminal
B) One synthetic bead coated with the enzyme alkaline phosphatase and a second synthetic bead coated with the substrate 4-nitrophenylphenol
C) One paramagnetic particle coated with anti IgG antibody and a second paramagnetic particle w coated with an IgG receptor antigen
D) One synthetic bead coated with Streptavidin that contains photosensitive dye and a second synthetic bead coated with a binding partner specific for the method and contains a chemiluminescent dye

Answer 2

One synthetic bead coated with Streptavidin that contains photosensitive dye and a second synthetic bead coated with a binding partner specific for the method and contains a chemiluminescent dye

Question 3

The antibody that binds to hapten-enzyme in the EMIT assay results in which of the following?

A) Enhancement of enzyme activity
B) Inhibition of enzyme activity
C) Inhibition of the enzyme substrate complex to reach first order kinetics
D) It has no effect on the reaction.

Answer 3

Inhibition of enzyme activity

Question 4

Which of the following best describes a procedural difference between homogeneous and heterogeneous immunoassays?

A) There is no physical separation of bound from free fractions in a homogeneous immunoassay whereas in a heterogeneous immunoassay you must separate bound forms from free forms.
B) A homogeneous immunoassay usually takes longer to perform because you must physically separate the bound from free fractions whereas in a heterogeneous immunoassay the time to perform the assay is shorter because you do not have to separate bound forms from free forms.
C) There is a physical separation of bound from free fractions in a homogeneous immunoassay.
D) Separation of bound and free fractions is optional for either type of immunoassays.

Question 5

Monoclonal antibodies typically recognize:

A) Multiple antigen sites.
B) Single antigen sites.
C) Only polar amino acids containing proteins.
D) Five different antigen sites.

Question 6

Which of the following immunoassays uses a gold electrode to facilitate production of light?

A) Electrochemiluminescence immunoassay
B) Fluorescence polarization immunoassay
C) Luminescent oxygen-channeling immunoassay
D) Substrate labeled fluorescent immunoassay

Question 7

Which of the following best describes haptens?

A) Haptens can be any substance capable of reacting with an antibody, but without necessarily being capable of inducing antibody formation.
B) Haptens are immunoglobulins capable of binding specifically to both natural and synthetic antigens.
C) Haptens are substances that are capable of binding an antibody but by themselves cannot stimulate an immune response.
D) Haptens are compounds that can be attached to antigens or antibodies and used as labels for immunoassays.

Question 8

A competitive immunoassay includes a patient analyte (antigen), antibody to the analyte (antigen), and which of the following?

A) A paramagnetic particle to which an antibody is attached
B) An antigen labeled conjugate
C) A label that is not attached to either an antibody or antigen
D) An antibody to the antibody-antigen complex

Question 9

In fluorescence polarization immunoassay (FPIA), the electrons in fluorescein molecules chemically attached to the hapten react in which of the following manner?

A) They do not spin at all.
B) They spin 100 times faster than normal.
C) They do not fluoresce.
D) They fluoresce.

Question 10

Plastic beads, polyclonal gels, and particles coated with iron oxide used in immunoassays are all examples of which of the following?

A) Antigen label
B) Solid phase material
C) Immunogens
D) Double antibodies

Question 11

Luminescent oxygen channeling immunoassay (LOCI) takes advantage of which of the following distance factors to initiate a chemiluminescent reaction?

A) Short diffusion distance of oxygen molecules in the first electronic state
B) Long diffusion distance of oxygen molecules in the first electronic state
C) Short absorption distances of oxygen
D) Short diffusion distance of hydrogen molecules in the first electronic state

Question 12

Microparticulate enzyme immunoassay uses which of the following enzymes to catalyze the conversion of the substrate, 4-methylumbelliferyl phosphate to methylumbelliferone?

A) Acid phosphatase
B) Alkaline phosphatase
C) Gamma-glutamyltransferase
D) Aldolase

Question 13

Which of the following is an example of a chemiluminescent compound?

A) Fluorescein
B) Luminol
C) Acridinium
D) Cis-platinum

Question 14

As the concentration of analyte begins to exceed the amount of antibody present, the dose response curve will flatten (plateau) and with further increase may become negatively sloped; this describes which of the following?

A) Logarithmic relationship of antibody concentration and millivolt output from the detector
B) Increase in precision
C) Loss of sensitivity
D) Hook effect

Question 15

Which of the following statements is TRUE regarding cloned enzyme donor immunoassays?

A) It uses a unique application of recombinant DNA technology to homogeneous immunoassay technique.
B) It uses a unique application of recombinant DNA technology to a heterogeneous immunoassay technique.
C) It uses a unique application of RNA receptor-capture technology to homogeneous immunoassay technique.
D) It uses an application of nano technology to competitive immunoassay technique.

Question 16

Which statement best defines an antigen?

A) Multiple molecular forms of an isoform
B) Immunoglobulin that is capable of binding specifically to both natural and synthetic antigens
C) A chemical substance capable of inducing an immune response
D) Any material capable of reacting with an antibody, without necessarily being capable of inducing antibody formation

Question 17

Which detector label is used in electrochemiluminescence immunoassays?

A) Fluorescein
B) Dioxetane
C) Ruthenium with tripropylamine
D) Glucose-6-phosphate dehydrogenase

Question 18

In fluorescent polarization immunoassay, a high concentration of sample analytes results in which of the following?

A) Increased emission of polarized light
B) Decreased emission of polarized light
C) Increased emission of nonpolarized light
D) Decreased emission of nonpolarized light

Question 19

Which of the following immunoassays produces a fluorescent molecule, 4-methylumbelliferone that serves as the detector compound?

A) Microparticulate enzyme immunoassay
B) Substrate labeled fluorescent immunoassay
C) Enzyme multiplied immunoassay
D) Fluorescent polarization immunoassay

Question 20

Affinity is described as which of the following?

A) The overall strength of binding of an antibody to an antigen and includes the sum of the binding affinities of all the individual binding sites on the antibody
B) Another substance that is capable of producing antibodies
C) The thermodynamic quantity defining the energy of interaction of a single antibody-binding site and its corresponding epitope on the antigen
D) A chemical substance capable of inducing an immune response