Immuno tb flashcards Unit 2

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Immuno TB Flashcards Unit 2

  1. On a serial dilution with the following tubes set up, 1:2, 1:4, 1:8, 1:16, 1:32, and 1:64, there is no visible agglutination in the 1:64 tube. What is the titer of the antibody?


  1. If you want to make a 4mL of a 1:20 dilution, how much serum would be needed?


  1. When a staphylococcal infection is passed between patients due to health-care workers not washing their hands, this represents an example of:

The chain of infection

  1. When 0.5mL of serum is added to 1.5mL of diluent, what dilution does this represent?


  1. Use of universal precautions is best explained how?

Treating every specimen in the lab as if it were infectious

  1. If 0.9mL of saline is added to 0.1mL of serum, what does the 0.9mL represent?

The diluent

  1. What is the main part of the federal Occupational Exposure to Bloodborne Pathogens Standard Act?

All employees must practice universal precautions at all times

  1. What applies to recapping of needles?

A) It can be done carefully as long as gloves are worn.

B) A sheath can be placed back on the needle with the other hand.

C) Transport needles back to the lab for disposal.

D) Never manually recap a needle.


  1. What should be part of a chemical hygiene plan?

appropriate work practices, engineering controls such as fume hoods, employee training

  1. Which series of dilutions would be best in order to make a 1:3000 dilution?

1:5, 1:6, 1:100

  1. Information on any potentially toxic substance used in a laboratory test kit would be found in:

material safety data sheet

  1. The strength of binding of one Fab on an immunoglobulin to one epitope on an antigen is referred to as


  1. A situation in which antibody is in excess as compared to antigen is called:


  1. A serological reaction is set up in which the antigen and antibody are both soluble and form an insoluble complex that is detected macroscopically. What type of assay was described?


  1. An Ouchterlony immunodiffusion assay is set up and a line of precipitation is seen forming between the antigen and antibody wells. The lines of precipitation formed by two adjacent antigen wells cross each other, forming an X. The reaction described is called:


  1. Your supervisor wants you to design a quantitative precipitation assay for a new diagnostic test. What methods would you adopt?

radial immunodiffusion

  1. The zone at which antibody and antigen are at optimal concentrations so that they form a large insoluble lattice together is called the:

equivalence zone

  1. In radial immunodiffusion, the diameter of the precipitin ring correlates with the:

concentration of antigen

  1. Affinity between individual antigen and antibody molecules depends on several types of bonds, such as ionic bonds, hydrophobic bonds, hydrogen bonds, and van der Waals forces. How is the strength of these attractions characterized?


  1. The radial immunodiffusion test is a method involving:


  1. An example of a qualitative precipitation procedure is:

A) Ouchterlony

B) radial immunodiffusion

C) rapid plasma reagin

D) complement fixation


  1. A situation in which antigen is in excess as compared to antibody is called:


  1. In an Ouchterlony immunodiffusion procedure, a continuous arc of precipitate is observed between two adjacent wells. This is a reaction of:


  1. In the Mancini endpoint method of RID:

The squared diameter is proportional to the concentration of antigen.

  1. Radial immunodiffusion combined with electrophoresis best describes what?

rocket immunoelectrophoresis

  1. Where does lattice formation occur to the greatest extent?

zone of equivalence

  1. When antibody combines with a particulate antigen, this is classified as which type of reaction?


  1. In what zones is a false-negative reaction likely?


  1. The initial force of attraction between an antigen and an antibody is called:


  1. What might adversely affect an electrophoresis reaction?

decreasing the strength of the current, changing the pH of the buffer, increasing the strength of the current

  1. Which technique is best to determine if two fungal antigens are identical?

Ouchterlony immunodiffusion

  1. The Western blot test used to confirm HIV is an example of what?


  1. Electrophoresis followed by diffusion of antibody from wells cut in the gel best describes what?


  1. Measurement of light scattered at an angle used to quantitate antigen–antibody complexes best describes:


  1. The force that keeps antigen and antibody together after the initial attraction and which is responsible for stability of the antigen–antibody complex is:


  1. What would be considered a single diffusion reaction?


  1. Precipitation reactions involve combination of soluble antibody with:

soluble antigen

  1. A serological reaction is set up in which the antigen is bound to a large carrier, the antibody is soluble, and they bind and form an insoluble complex that is detected macroscopically. What type of assay is described?


  1. A serological test that uses red blood cells coated with exogenous antigens such as bacterial polysaccharides as a method to detect patient antibodies against that exogenous antigen is called:


  1. The process by which particulate antigens such as cells aggregate to form larger complexes when specific antibody is present is called:


  1. In performing blood typing using the tube method, if the red cell button is not resuspended properly, what are the most likely results?


  1. When a patient's red blood cells combine with anti-A typing serum to produce a positive result, this reaction is known as:


  1. When carrier particles are coated with an antigen that is not normally found on them, this is known as:

passive agglutination

  1. If a Coombs' test is positive, what is true?

Antibody has coated patient red blood cells in vivo.

  1. Coombs' reagent is used for what purpose?

to enhance agglutination with IgG coated red blood cells

  1. What would be the best test to determine evidence of hemolytic disease of the newborn?

direct antiglobulin testing

  1. What would enhance an agglutination reaction?

polyethylene glycol (PEG)

  1. Which antibody class may require the use of an enhancement technique to visualize the reaction?


  1. An immunoassay is performed in the following manner to look for an Ag in the patient serum: Patient serum + labeled Ag + known Ab are added together and incubated. Unbound material is washed off. The amount of labeled Ag is then measured. What assay is performed?

competitive EIA

  1. An ELISA assay was performed on a patient's serum sample. What is the relationship of the amount of enzyme activity to the amount of patient analyte measured?

directly proportional

  1. An immunoassay was performed in the following way: Antigen is bound to a solid support. Patient serum is added and patient antibodies bind to the antigen. The well is washed and enzyme-labeled anti-immunoglobulin antibodies are added. The well is washed and enzyme substrate is added and enzyme activity is determined. Which immunoassay is described?


  1. Indirect immunofluorescence is similar to which type of enzyme immunoassay as far as the performance of the assay?


  1. What best describes competitive binding assays?


A limited number of binding sites are present.


Concentration of patient antigen is directly proportional to the label detected.


All patient antigen present is allowed to bind.


Labeled and unlabeled analyte are present in equal amounts.


  1. All of the following are characteristic of noncompetitive enzyme immunoassays EXCEPT:


They are more sensitive than agglutination reactions.


Concentration is directly proportional to the amount of color.


Washing carefully is very important.


Binding sites for patient antibody are limited.


  1. What best describes homogeneous assays?


A washing step is necessary.


Concentration of patient antigen is directly proportional to the label detected.


The reagent antibody has an enzyme tag.


Labeled and unlabeled analyte are present in equal amounts.


  1. In the following equation, what is the ratio of bound radioactive antigen to bound patient antigen? 8ag* + 4ag + 6ab ---> ag*ab + agab + ag* + ag

Explanation: The original 8 to 4 ratio stipulates that there are twice as many radioactive antigens competing, so it would figure that there would be the same ratio of bound set as well, given equal affinity/binding. See text page 154.  

  1. What is characteristic of noncompetitive enzyme immunoassays?


Binding sites for patient antigen are limited.


Washing in between steps is not necessary.


All patient antigen is allowed to react with binding sites.


Color is indirectly proportional to the concentration.


  1. Components of a competitive immunoassay include all of the following EXCEPT:


labeled analyte


means of detection of the label


solid-phase antibody


standard different from the analyte


  1. In an indirect fluorescent immunoassay such as the FTA confirmatory test for syphilis, all of the following are true EXCEPT:


A labeled antigen is used.


Washing is an important step.


Patient antibody is detected.


Antihuman globulin has a fluorescent tag.


  1. In a sandwich or capture assay to determine the presence of a viral antigen in a patient sample, what would be on solid phase?

unlabeled antibody

  1. In What testing situations is there a direct relationship between the amount of bound label and the amount of patient antigen present?

noncompetitive EIA using a second labeled antibody

  1. In the following equation, 10 Ag* + 5 Ag + 3 Ab ---> Ag*Ab + Ag Ab + Ag* + Ag, the ratio of bound radioactive antigen to bound patient antigen is:


  1. Pregnancy testing is based on an early increase in which hormone?

human chorionic gonadotropin

  1. Restriction endonucleases used in DNA analysis are characterized by all of the following EXCEPT:

They cleave both DNA and RNA.

  1. What is meant by semi-conservative replication of DNA?

Each strand is the template for another strand.

  1. In order for a probe to hybridize to the target, which condition must be met?

The target must have complementary bases.

  1. Restriction fragment length polymorphisms are characterized by all of the following EXCEPT:

A) Their DNA base sequences are the same.

B) Different DNA bases result in cleavage at different places.

C) They are detected by gel electrophoresis.

D) Different patterns can be used for identification purposes.


  1. A reaction characterized by amplification of a specific region of a DNA strand through denaturing and annealing best describes what?

A) signal amplification

B) polymerase chain reaction

C) solution hybridization

D) ligase chain reaction

polymerase chain reaction

  1. A short strand of DNA or RNA used to detect an unknown nucleic acid in a patient specimen best describes a:

A) nucleic acid probe

B) restriction enzyme

C) primer

D) restriction fragment length polymorphism

nucleic acid probe

  1. Which is the correct conclusion if results of DNA restriction analysis by gel electrophoresis show a difference in one band?

A) The samples are the same.

B) The samples are not identical.

C) Gel electrophoresis should be repeated.

D) The wrong buffer was used in electrophoresis.

The samples are not identical.

  1. Which type of RNA is used to directly translate the DNA code into making functional proteins?

A) transfer RNA

B) ribosomal RNA

C) messenger RNA

D) probe RNA

messenger RNA

  1. What steps are included in a Southern blot?

A) ligation of DNA probes by a DNA ligase

B) gel electrophoresis followed by transfer of the pattern to a membrane

C) denaturation of DNA followed by annealing of primers and bases

D) creating a nick in a DNA strand followed by amplification

gel electrophoresis followed by transfer of the pattern to a membrane

  1. In which technique is the signal amplified instead of the actual target DNA?

A) branched DNA amplification


C) transcription-mediated amplification

D) solution hybridization

branched DNA amplification

  1. In DNA sequencing, what is the purpose of the dideoxynucleotide bases?

A) to enhance synthesis of DNA

B) to stop growth of a DNA chain at a certain point

C) to make certain that only one strand of DNA is amplified

D) to create restriction fragment length polymorphisms

to stop growth of a DNA chain at a certain point

  1. Use of microarrays consisting of either DNA or RNA to identify an unknown nucleic acid best describes:

A) in situ hybridization

B) polymerase chain reaction

C) DNA chip technology

D) strand displacement amplification

DNA chip technology

  1. What would be an advantage of using molecular diagnostic techniques in identification of specific HLA antigens instead of serological techniques?

more specific, more rapid

  1. What is meant by “gating” in flow cytometry?

A) the chromatic arrangement of cellular populations

B) process by which one cell population adheres to another population

C) an electronic window separating subpopulations of cells

D) an electronic device measuring all populations of cells

an electronic window separating subpopulations of cells

  1. A mature cytotoxic T cell expresses which markers?

CD8, CD3, and CD2

  1. What is an intrinsic parameter that can be measured by a flow cytometer?

internal complexity

  1. As measured in flow cytometry, cells that are the smallest and have the least granules would be identified as:


  1. In most flow cytometers, labeled cells:

scatter the light and emit fluorescence

  1. The expression of cell surface markers is determined in the flow cytometer by what?


  1. In flow cytometry, if there are two light detectors, what does the amount of side scatter indicate?

granularity of the cell

  1. Which is a difference between batch and random access analyzers?

Batch analyzers only do one type of analysis at a time.

  1. If a test system has many false-positive results, this is a problem involving:


  1. A range of values that all produce a positive result is known as:

reportable range

  1. Anaphylactic reactions are mediated by:

mast cells

  1. The radioimmunosorbent assay can be used for the diagnosis of which type of hypersensitivity?


  1. Reaction to poison ivy is which type of hypersensitivity?


  1. Immune injury resulting from the localization of immune complexes in blood vessels and tissues describes which hypersensitivity reaction?


  1. Which isotype of immunoglobulin is involved in a type I hypersensitivity?


  1. What diseases is an example of a type II hypersensitivity?

myasthenia gravis

  1. Hypersensitivities to poison ivy (catechol) and nickel are:

macrophage responses to a hapten

  1. Type II hypersensitivity could involve all of the following EXCEPT:

A) IgE cross-linking on the mast cell or basophile

B) phagocytic cell degranulation and proteolytic enzyme activity

C) a kidney membrane antigen and specific antibody

D) natural killer cell activation and killing


  1. The principle difference between type II and type III hypersensitivity reactions is the:

whether the antigen is cellular or soluble

  1. The normal activity of a type I hypersensitivity response is protection primarily against what?


  1. An example of a type III hypersensitivity is:

rheumatoid arthritis

  1. All of the hypersensitivity responses have what in common?


  1. Preformed mediators that are released during the activation phase of a type I hypersensitivity include what?


  1. A 5-year-old girl was rushed to the emergency department because she was having trouble breathing. She had been playing at the park when she fell down and her face and neck started to swell up. One of her friends thought that the girl might have been stung by a bee because a bee was flying around them and shortly before the girl fell to the ground, she had screamed. The girl had a large red bump on her cheek. This girl has:

type I hypersensitivity

  1. A hypersensitivity reaction characterized by presence of IgG that reacts with soluble antigen best describes:

type III hypersensitivity

  1. All of the following hypersensitivity reactions involve activation of complement EXCEPT:

A) allergic reactions

B) hemolytic disease of the newborn

C) autoimmune hemolytic anemia

D) serum sickness


  1. Anaphylaxis is characterized by all of the following EXCEPT:

A) IgE-coated mast cells

B) massive release of histamine

C) bronchoconstriction

D) circulating immune complexes


  1. What occurs in hemolytic disease of the newborn?

Rh– Mom's exposure to Rh+ baby cells

  1. Precipitation of immune complexes in small blood vessels under the skin that occurs when antigen is injected in an animal with large amounts of circulating antibody describes what?

Arthus reaction

  1. All of the following are involved in killing of large parasites EXCEPT:

A) degranulation of mast cells

B) action of eosinophil basic protein

C) production of IgE

D) activation of complement


  1. The immune mechanism involved in contact dermatitis is what?

sensitization of cytotoxic T cells

  1. In a direct antiglobulin test, what is being detected?

in vivo attachment of antibodies to red blood cells

  1. To determine if a patient is allergic to peanuts, the best test to perform is:


  1. An exaggerated reaction directed against an antigen that is harmless is called:


  1. What is true of immediate hypersensitivity reactions?

Histamine is released from mast cells, Antigen must bind to two IgE molecules, Eosinophil chemotactic factor is released.

  1. All of the following are characteristic of cold autoimmune hemolytic anemia EXCEPT:

A) The antibody responsible is IgG.

B) It is usually in older patients.

C) The antibody reacts as an anti-I.

D) The reaction is only seen at cold temperatures.


  1. The PPD reaction to determine exposure to tuberculosis is based on what?

a sensitized T-cell response

  1. Reasons for autoimmunity include all of the following EXCEPT:

A) antibody that cross-reacts with self-antigens

B) inheritance of certain MHC antigens

C) molecular mimicry

D) deletion of self-reactive lymphocytes during maturation


  1. Complement is responsible for tissue damage in what reactions?

cytotoxic reactions

  1. T cell–dependent hypersensitivity occurs:

24 to 72 hours after exposure to the antigen

  1. Anaphylaxis is characterized by what?

degranulation of mast cells

  1. Cold autoimmune hemolytic anemia is an example of which type of hypersensitivity?

type II

  1. Complement is responsible for tissue damage in what reactions?

type III hypersensitivity

  1. A positive DAT test might indicate what?

autoimmune hemolytic anemia

  1. What is a test for antibody to a specific allergen?


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