OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response | UPDATE

T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 1 of 18 Chapter 20: Laboratory Analysis of the Immune Response * = Correct answer Multiple Choice 1. Most antigens have how many epitopes? A. none B. one C. two D. more than two* Difficulty: Easy ASM Standard: N/A 2. Which best describes monoclonal antibodies? A. They are produced in living animals only. B. They are produced in tissue cultures, using B cells extracted from living animals.* C. They are rarely used, so polyclonal antibodies are preferred. D. They can be produced in either living animals or tissue cultures. Difficulty: Easy ASM Standard: N/A 3. A hybridoma is which of the following? A. a cancerous cell B. a fusion of a B cell and a T cell C. a fusion of a normal B cell and a myeloma cell* D. a hybrid of two cancerous cells Difficulty: Easy ASM Standard: N/A 4. Which is the correct term for a visible antigen-antibody complex? A. epitope B. heavy chain complex C. hybridoma D. precipitin* Difficulty: Easy ASM Standard: N/A 5. Monoclonal antibodies bind to which of the following? A. a single epitope* B. a single hybridoma C. multiple epitopes TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 2 of 18 D. variable numbers of epitopes Difficulty: Easy ASM Standard: N/A 6. Double immunodiffusion is also known as which of the following? A. flocculation assay B. Ouchterlony assay* C. precipitin ring test D. radial immunodiffusion assay Difficulty: Moderate ASM Standard: N/A 7. Which technique is used to help view tissues, using microscopy? A. electrophoresis B. immunostaining* C. lateral flow assays D. western blotting Difficulty: Easy ASM Standard: 32 8. Which technique could be used to rapidly diagnose strep throat or mycoplasma pneumonia by labeling bacteria with fluorescent monoclonal antibodies? A. brightfield microscopy and ELISA techniques B. fluorescence microscopy and direct fluorescent antibody techniques* C. immunohistochemistry and immunostaining techniques in varying combinations D. western blotting with chromogens or fluorogens Difficulty: Easy ASM Standard: 32 9. Which of the following describes antiserum? A. a type of vaccine produced in the laboratory B. antibodies obtained by exposing blood to an antigen in the lab C. monoclonal antibodies obtained from the blood of an animal injected with an antigen D. whole serum containing antibodies obtained from an animal exposed to an antigen* Difficulty: Moderate ASM Standard: N/A 10. When does an antibody test result in a false positive? A. An individual tests as though she does not have the antigen even though she does. B. An individual tests as though she has the antigen even though she does not.* C. Antibodies bind to the antigen too strongly, causing an error in the testing protocol. TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 3 of 18 D. Variations in antibodies cause them to fail to bind to an antigen that is present. Difficulty: Moderate ASM Standard: N/A 11. Test sensitivity is defined as which of the following? A. the probability that an individual will have a false-positive test result B. the probability that an individual with an infection will test positive* C. the probability that an individual with an infection will test negative D. the probability that a test will detect multiple antigens simultaneously Difficulty: Moderate ASM Standard: N/A 12. Which of the following most commonly results from exposure to a single antigen? A. A single antibody is produced that can respond to multiple antigens. B. A single antibody is produced that is specific to that antigen. C. Multiple antibodies are produced because antigens usually have multiple epitopes. D. Multiple antibodies are produced to respond to a single epitope.* Difficulty: Moderate ASM Standard: N/A 13. When a particular test rarely produces false negatives, it has which of the following? A. high sensitivity* B. high specificity C. low sensitivity D. low utility Difficulty: Moderate ASM Standard: N/A 14. Compared with the production of polyclonal antibodies, the production of monoclonal antibodies is which of the following? A. completed without hybridomas B. easier and faster C. less expensive D. more expensive* Difficulty: Moderate ASM Standard: N/A 15. Which type of antibody is preferable for western blot tests and why? A. monoclonal antibodies, because they are more sensitive and produce a clearer signal B. monoclonal antibodies, because they are more specific and less expensive TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 4 of 18 C. polyclonal antibodies, because they are able to bind to specific epitopes even though they are more expensive D. polyclonal antibodies, because they can bind to multiple epitopes, generally produce a stronger signal, and are less expensive* Difficulty: Moderate ASM Standard: N/A 16. What problem makes it difficult to use humanized monoclonal antibody cocktails to treat pathogens? A. It is less expensive to use monoclonal antibody cocktails rather than purified monoclonal antibodies. B. It is too technically difficult to separate out the different monoclonal antibodies. C. Monoclonal antibodies are not sufficiently strong to target pathogens without being used in high concentrations. D. Monoclonal antibodies are so specific that they may not target all serovars of a pathogen.* Difficulty: Moderate ASM Standard: N/A 17. Which technique has been proposed to make less-expensive monoclonal antibodies? A. They can be humanized so that they are easier to use in humans. B. They can be produced in complex mixtures rather than in purified versions. C. They can be produced in genetically engineered plants as plantibodies.* D. They can be produced using RT-PCR techniques. Difficulty: Moderate ASM Standard: N/A 18. ZMapp is an experimental drug that appeared to be a promising treatment during the 2014– 2015 Ebola outbreak. Which is a major limitation to using this type of medication? A. ZMapp consisted of polyclonal antibodies, so it was not sufficiently specific to work effectively. B. ZMapp consisted of three monoclonal antibodies to treat multiple Ebola strains, making it prohibitively expensive even if available in sufficient quantities.* C. ZMapp was produced by genetically engineered plants and the virus used to introduce it into plants could cause a problematic immune response in humans. D. ZMapp was produced in tissue cultures, which is a slow and laborious process that can’t be used to make medications in bulk quantities. Difficulty: Moderate ASM Standard: N/A 19. Which of the following correctly describes the effect of a particular factor of a precipitin reaction on the amount of precipitin formed? A. A 1:1 ratio of antibody to antigen yields the maximum amount of precipitate. TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 5 of 18 B. Monoclonal antibodies generally bind more and, therefore, produce more precipitate than polyclonal antibodies. C. The greater the affinity of the antibody for the antigen, the greater the amount of precipitate.* D. The lack of a lattice increases precipitation compared with the presence of a lattice. Difficulty: Moderate ASM Standard: N/A 20. The precipitin ring test is used to do which of the following? A. qualitatively identify the presence of a particular antibody in an antiserum B. quantify the relative amount of a specific antibody present in an antiserum only* C. quantify the relative amount of a specific antigen present in an antiserum only D. quantify the relative amounts of a specific antibody and the antigen to which it binds present in an antiserum Difficulty: Moderate ASM Standard: N/A 21. Which is the formal definition of an antibody titer? A. It is a fractional expression of the highest dilution of serially diluted antibody that results in visible precipitation. B. It is a whole-number expression of the reciprocal of the highest dilution of serially diluted antibody that results in visible precipitation.* C. It represents the highest dilution in a serial dilution test that shows a positive result, rounded to a whole number. D. It represents the total number of dilutions needed to get a positive result. Difficulty: Moderate ASM Standard: N/A 22. What is a major difference between the precipitin reaction test and flocculation assays? A. Only flocculation involves a visible lattice of antibody and antigen. B. Only flocculation involves the observation of lipids foaming in a positive result.* C. Only flocculation involves the observation of precipitate in a positive result. D. Only flocculation involves the use of a serial dilution technique. Difficulty: Moderate ASM Standard: N/A 23. A plaque reduction assay is used to quantify which of the following? A. antibodies produced by a patient during a bacterial infection B. antibodies produced by a patient during a viral infection* C. antigens produced by a bacterium during a bacterial infection D. antigens produced by a virus during viral infection TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 6 of 18 Difficulty: Moderate ASM Standard: N/A 24. Which test would be most helpful in further examining abnormal patterns of protein abundance previously identified using a PAGE assay? A. a neutralization assay B. a precipitin ring test C. an indirect ELISA test D. immunoelectrophoresis* Difficulty: Moderate ASM Standard: N/A 25. Glycerol is used during the precipitin ring test to do which of the following? A. form a seal to prevent evaporation of the antiserum and antigen B. fully dissolve the antiserum and antigen into a homogenous solution C. prevent the antiserum and antigen solutions from mixing at all D. prevent the antiserum and antigen solutions from mixing except at their interface* Difficulty: Difficult ASM Standard: N/A 26. Why is cross-matching needed before a blood transfusion? A. Cross-matching is a final check before transfusion that involves mixing the patient’s blood with a small sample of the blood to be transfused as an additional check.* B. Cross-matching is the first attempt to make sure the blood is compatible before more thorough testing. C. Cross-matching refers to checking the needed blood type and the blood type of the patient before ordering blood for transfusion. D. Cross-matching would be needed for planned surgery but is a quality control measure not necessary in an emergency situation. Difficulty: Difficult ASM Standard: N/A 27. What causes jaundice and how would the presence of maternal antibodies affect newborn jaundice? A. Jaundice is caused by excessive breakdown of blood cells; the maternal antibodies activate complement and begin this process.* B. Jaundice is caused by excessive quantities of red blood cells, so having maternal antibodies to the newborn’s cells would reduce the risk of jaundice. C. Jaundice is caused by the breakdown of blood cells; maternal antibodies inhibit complement production and the newborn’s blood cells, therefore, are vulnerable to destruction. D. Jaundice is caused by the breakdown of blood cells; maternal antibodies inhibit this process and reduce the risk of jaundice. TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 7 of 18 Difficulty: Difficult ASM Standard: N/A 28. Why is a direct hemagglutination assay helpful in detecting the influenza virus? A. A human cell infected by the influenza virus produces a protein called neuraminidase on its surface that can cross-link red blood cells. B. The influenza virus has a protein called hemagglutinin on its capsid that can cross-link red blood cells.* C. The influenza virus has a protein called neuraminidase on its surface that can cross-link red blood cells. D. The influenza virus has multiple proteins on its capsids (hemagglutinin and neuraminidase) that can cross-link red blood cells. Difficulty: Difficult ASM Standard: N/A 29. Which test can be used to determine titers of antiviral antibodies in a patient’s serum? A. the Coombs’ test B. the cross-matching test C. the direct hemagglutination assay D. the viral hemagglutination inhibition assay* Difficulty: Difficult ASM Standard: N/A 30. Which of the following is not used as a mechanism to detect the presence of antigen in a sample in EIA protocols? A. When the antigen binds to the antibody, antibody with a bound enzyme will cleave a colorless fluorogen that fluoresces. B. When the antigen binds to the antibody, antibody with bound alkaline phosphatase will cleave a colorless substrate, releasing a colored product. C. When the antigen binds to the antibody, antibody with bound horseradish peroxidase will cleave a colorless substrate, leaving a colored product. D. When the antigen binds to the antibody, the antigen-antibody complex will precipitate, forming an easily observable line at the interface.* Difficulty: Difficult ASM Standard: 32 31. If you performed a direct ELISA but failed to add the chromogen, which of the following would happen? A. The antibody would be less visible in the wells if present. B. The antibody would be unable to bind to the antigen. C. The antibody would detach from the enzyme. D. The antibody would not be visible even if present.* TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 8 of 18 Difficulty: Difficult ASM Standard: N/A 32. Why would a spectrophotometer be helpful in interpreting the results of a sandwich ELISA? A. It would allow for visualization of the antibody-antigen complex. B. It would allow one to use a single test to differentiate previous exposure from acute infection. C. It would be faster, although less sensitive. D. It would provide more information because the absorbance measured would be proportional to the amount of antigen in the wells.* Difficulty: Difficult ASM Standard: N/A True/False 33. The production time for monoclonal antibodies is much faster than the production time for polyclonal antibodies. Answer: False Difficulty: Easy ASM Standard: N/A 34. Lateral flow tests are inexpensive and easy to perform, which has enabled the development of a wide range of diagnostic tests for home use based upon this technology. Answer: True Difficulty: Easy ASM Standard: N/A 35. In direct ELISA testing, a patient’s sample is added to a well with immobilized antibodies already present in its base. Answer: False Difficulty: Moderate ASM Standard: N/A 36. A positive indirect ELISA test is sufficient to make an HIV diagnosis. Answer: False Difficulty: Moderate ASM Standard: N/A 37. CD8 cells can be detected in host tissue by using immunostaining. Answer: True TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 9 of 18 Difficulty: Moderate ASM Standard: N/A 38. A typical home pregnancy test is a lateral flow test that detects human chorionic gonadotrophin in urine. Answer: True Difficulty: Moderate ASM Standard: N/A 39. Seroconversion occurs relatively quickly once someone is exposed to HIV, so detection of antibodies against HIV is recommended using ELISA within a week after exposure. Answer: False Difficulty: Difficult ASM Standard: N/A 40. One test involved in diagnosing systemic lupus erythematosus involves detecting antinuclear antibodies by using indirect fluorescent antibody detection. Answer: True Difficulty: Difficult ASM Standard: N/A Matching 41. Match each type of assay with an important application of its use. A. direct agglutination i. diagnosis of influenza B. direct hemagglutination ii. testing patients for rheumatoid factor C. indirect agglutination iii. pretransfusion blood testing D. indirect hemagglutination iv. serotyping bacteria Answers: A. iv., B. i., C. ii., D. iii. Difficulty: Moderate ASM Standard: N/A 42. Match each type of immunoblot or enzyme immunoassay with the best description. A. enzyme-linked immunosorbent assay i. Proteins are transferred to a membrane and then identified using enzyme-antibody conjugates. B. immunoblots ii. Specific molecules are stained using enzyme-antibody conjugates. C. immunochromatographic assays iii. Target molecules are quantified using enzyme-antibody conjugates that bind to them. TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 10 of 18 D. immunostaining iv. Varied techniques that use fixed antibody to capture flowing, labeled antigen-antibody complexes. Answers: A. iii., B. i., C. iv., D. ii. Difficulty: Moderate ASM Standard: N/A 43. Match each type of assay with a specific procedure that exemplifies it. A. enzyme-linked immunosorbent assay i. direct or indirect ELISA B. immunoblots ii. immunohistochemistry C. immunochromatographic assays iii. sandwich ELISA D. immunostaining iv. western blotting Answers: A. i., B. iv., C. iii., D. ii. Difficulty: Easy ASM Standard: N/A 44. Match each fluorescent antibody technique with its best description. A. direct fluorescent antibody i. used to detect antibodies for a particular disease from a patient’s serum sample BC. flow cytometry ii. used to label pathogens from patients’ samples with fluorogen-antibody conjugates for detection CD. fluorescence-activated cell sorter iii. used to separate cells into subpopulations via a device that adds charges to fluid droplets DB. indirect fluorescent antibody iv. used to count cells that have been labeled with fluorogen-antibody conjugate markers, using a laser Answers: A. ii., B. iv., C. iii. D. i. Difficulty: Difficult ASM Standard: N/A Fill in the Blank 45. PAGE is the abbreviation for ________. Answer: polyacrylamide gel electrophoresis Difficulty: Easy ASM Standard: N/A 46. Often used to identify a molecule of interest, a(n) ________ is a molecule that can be made to fluoresce. Answer: fluorochrome Difficulty: Easy ASM Standard: N/A TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 11 of 18 47. The product of the fusion of a cancerous B cell (a myeloma cell) with a normal B cell is called a(n) ________. Answer: hybridoma Difficulty: Moderate ASM Standard: N/A 48. Manufactured antibodies designed to bind to a single epitope are called ________. Answer: monoclonal antibodies Difficulty: Moderate ASM Standard: N/A 49. The test used to identify proteins after protein gel electrophoresis is called the ________ test. Answer: western blot Difficulty: Moderate ASM Standard: N/A 50. After ________, the antibody levels in a patient’s serum are high enough for detection, enabling diagnosis. Answer: seroconversion Difficulty: Moderate ASM Standard: N/A 51. Lattice formation is detected using the ________ ring test. Answer: precipitin Difficulty: Moderate ASM Standard: N/A 52. Flocculants are formed by ________ antigens in a suspension. Answer: insoluble Difficulty: Moderate ASM Standard: 53. Plates that allow multiple reactions to be run side by side in a small area, such as those used in ELISA testing, are called ________ plates. Answer: microtiter Difficulty: Moderate ASM Standard: N/A TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 12 of 18 54. Because antibodies can cause bacterial serovars to clump, ________ assays based on this characteristic can be used to identify the serovars. Answer: agglutination Difficulty: Difficult ASM Standard: N/A 55. Herceptin is an example of a(n) ________ that can be used to treat cancer. Answer: monoclonal antibody (or humanized monoclonal antibody) Difficulty: Difficult ASM Standard: N/A Short Answer 56. Why is a chromogen used in ELISA testing? Sample Answer: A colorless chromogen reacts with the enzymes in the reaction so positive samples can be recognized by their color. Difficulty: Easy ASM Standard: N/A 57. If you do a neutralization assay and find there are antibodies to a virus, does that mean the patient has a current infection with that virus? Why or why not? Sample Answer: No, the patient may have had a previous exposure. It is necessary to do a second assay to monitor changes in antibody level to determine whether an infection is current. Difficulty: Easy ASM Standard: N/A 58. What is flocculation? Sample Answer: Flocculation is the foaming that occurs during the flocculation assay from the reaction of antibodies and antigens. Difficulty: Easy ASM Standard: N/A 59. What does ELISA stand for? Sample Answer: ELISA is the acronym for enzyme-linked immunosorbent assay. Difficulty: Easy ASM Standard: N/A 60. Why is a chromogenic substrate sometimes used in western blotting? TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 13 of 18 Sample Answer: An antibody can be bound to an enzyme that can react with the chromogenic substrate. When an enzyme reacts with this substrate, a visible color is produced. The color provides an indication that the enzyme, and, therefore, the antibody, is present. Difficulty: Easy ASM Standard: N/A 61. How do direct and indirect ELISA differ? Sample Answer: In direct ELISA, immobilized antigens in microtiter plates are exposed to an antibody-enzyme conjugate that binds if the antigens are present. A chromogen enables bound antibody-antigen complexes to be identified, allowing the researcher to know whether the antigen is present. In indirect ELISA, known antigen is attached and then a sample from a patient is added so that any antibodies in the sample will bind to the antigen. A secondary antibody with a conjugated enzyme is added to identify whether antibodies were present in the patient sample. The figure below illustrates the process. TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 14 of 18 Difficulty: Moderate ASM Standard: N/A 62. What is a disadvantage of using monoclonal antibodies to detect bacterial serovars? TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 15 of 18 Sample Answer: Monoclonal antibodies are so specific that they may not detect all serovars of a bacterium. Difficulty: Moderate ASM Standard: N/A 63. You want to test whether a patient has a current viral infection. You conduct a first neutralization assay and then conduct a second assay after 2 weeks. You find that a onefourth dilution is the greatest dilution that produces a 50% plaque reduction for the first assay. For the second assay, you find that a 1/32 dilution is the greatest dilution that produces a 50% plaque reduction. What were the patient’s titers for the first and second tests? Does the patient have a current infection? Sample Answer: The patient’s titers were four for the first test and 32 for the second test, so the patient does have a current infection. Difficulty: Moderate ASM Standard: N/A 64. How is IEP useful in diagnosing multiple myeloma? Sample Answer: IEP (immunoelectrophoresis) is useful in diagnosing multiple myeloma because patients with this type of cancer cannot produce normal antibodies; instead, they produce abnormal antibodies that show up in a distinctive pattern on an electrophoresis gel. Difficulty: Moderate ASM Standard: N/A 65. How does southwestern blotting differ from western blotting? Sample Answer: Western blotting involves the identification of proteins blotted from a polyacrylamide gel subjected to electrophoresis to separate the proteins. In southwestern blotting, SDS-PAGE is used and then the blotted proteins are exposed to a labeled DNA probe. This enables identification of DNA-protein interactions. Southern blotting is used to examine DNA, whereas western blotting is used to examine proteins. Thus, southwestern blotting gets its name because it looks for interactions between DNA and proteins. Difficulty: Moderate ASM Standard: N/A 66. What is the purpose of the complement fixation test? Sample Answer: It is used to detect the presence of a pathogen by detecting the presence of antibodies directed toward some component of the pathogen. Difficulty: Moderate ASM Standard: N/A 67. Why are red blood cells especially useful for evaluating complement-mediated cytolysis and for the complement-fixation test? TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 16 of 18 Sample Answer: When red blood cells lyse, they release hemoglobin and cause the solution to become pink to red. (Complement can cause cell lysis. In the complement-fixation test, a sample of patient serum is used. Pathogen antigen is added. If the patient has been exposed to the pathogen and has antibodies, the antibodies will bind to the antigen and the available complement will be fixed. The addition of red blood cells and antibodies to red blood cells will not cause a color change, because there is no complement left to lyse the red blood cells. If antibodies to the pathogen are not present, then the presence of complement allows lysis of the red blood cells and the solution will become pink from the release of hemoglobin.) Difficulty: Difficult ASM Standard: N/A 68. During the complement fixation test, why is it necessary to heat patients’ samples? Sample Answer: Heating destroys complement that is already present, allowing the researcher to control the amount of complement. Difficulty: Difficult ASM Standard: N/A 69. Give an example of a clinical test that uses flocculation. Sample Answer: There are multiple possible answers, but the book mentions the VDRL test for syphilis. Difficulty: Difficult ASM Standard: N/A 70. How would your results be affected if you did an indirect ELISA test and did not sufficiently rinse the patient serum from the plates before adding the secondary antibody-enzyme complex? Why would this occur? Sample Answer: This could cause false-positive results due to cross-reactivity with other components of the serum. Difficulty: Difficult ASM Standard: N/A Brief Essay Essay Question Rubric RATING Failing Below Average Competent Advanced TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 17 of 18 Criteria for evaluation Answer does not provide an argument. Answer contains inaccuracies. Writing is poor and contains numerous grammatical mistakes and misspellings. Answer fails to provide examples to support an argument. Writing is poor and grammatical errors are common. Answer is somewhat incoherent. Answer provides an argument with one or two examples that support it. Writing is acceptable for the college level but may contain one or two grammatical mistakes or misspellings. Answer clearly provides an argument with two or more excellent examples that support it. Student makes the argument clearly and eloquently. Answer is well organized and free of grammatical errors and misspellings. POINT VALUE 0 1 2 3 Assume rating/grading scale for the question ranges from 0 to 3 points. 71. Explain the process used to produce polyclonal antibodies. Answer: Student answers will vary but should include components of the stages shown in Figure 20.3. These include injection of an antigen into an animal (which is usually done twice), the activation of B cells in response to antigen exposure, the production of polyclonal antibodies by plasma B cells, and the extraction of antiserum from the animal to obtain the antibodies. In many cases, the antiserum must be purified to remove antibodies other than those of interest. Difficulty: Moderate ASM Standard: N/A 72. Why would it be a problem to inject monoclonal antibodies from mouse cells directly into humans? How is this problem addressed? Answer: Student answers will vary but should include the following. Humans would develop an immune response to the mouse antibodies and neutralize them, so the antibodies have to be “humanized.” This is accomplished by using genetic engineering to produce a gene for a human antibody with only the antigen-binding site from the mouse antibody. The antigenbinding site is the critical component to recognize and bind to the desired antigen. Difficulty: Moderate ASM Standard: N/A 73. Explain the trade-offs involved in evaluating sensitivity and specificity in choosing a test for the detection of HIV. In your answer, reference the types of HIV tests currently used. Answer: Student answers will vary but should include the following. Students may choose to discuss the use of the western blot test (immunoblotting) as an example of a test currently used for HIV detection. Other possible tests mentioned in the chapter for HIV detection include agglutination, ELISA, nucleic acid antigen, and RT-PCR tests. Students should address the potential harm from someone being told they are infected when they are not (as is TESTBANKSELLER.COM TESTBANKSELLER.COM #1 TEST BANKS WHOLESALER T E S T B A N K S E L L E R . C O M OpenStax Microbiology Test Bank Chapter 20: Laboratory Analysis of the Immune Response Page 18 of 18 more likely with a test that lacks specificity) or of being told they are not infected when they are (as is more likely with a test that lacks sensitivity). Ideally, students should discuss the way initial testing (such as indirect ELISA) must be confirmed with additional testing (such as RT-PCR or immunoblotting). Difficulty: Difficult ASM Standard: 31a 74. New testing approaches will make it easier for people to test for diseases such as HIV at home, as with a home pregnancy test. Discuss the pros and cons of the increased use of direct-to-consumer sales of tests for such serious illnesses. Include an overview of some of the types of tests that are facilitating this trend. Answer: Student answers will vary but should include the following. The types of tests that are easy to use at home include lateral flow tests (used in home pregnancy tests) and lab-ona-chip technology. Students may discuss the convenience, reduced expense, and increased testing access associated with over-the-counter testing. However, they should also discuss the ethical concerns such as receiving a devastating diagnosis without the presence of a healthcare professional for immediate advice and support. Difficulty: Difficult ASM Standard: 31 This file is copyright 2017, Rice University. All rights reserved. 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