MLT 243 Exam 2023 Questions And Answers.

MLT 243 Exam 2023 Questions And Answers. In performing routine quality control on a particular laboratory test, a high-quality control value is obtained that changes the mean. What type of change does this represent? - ANSWER shift What does the acronym RACE stand for? - ANSWER rescue, alarm, contain, extinguish A patient under isolation precautions is being transported to the x-ray department. He has no mask on and sneezes in the elevator. This scenario is an example of what type of hazard? - ANSWER Chain-of-infection hazard A coworker says she has an allergy to latex. As her supervisor, what should you advise her to do? - ANSWER Wear gloves made of an alternative material. A blood spill occurs in the immunology laboratory. What should you do? - ANSWER Make a 1:10 solution of bleach and wash the area. What is the most appropriate laboratory safety wear? - ANSWER Fluid-resistant laboratory gown with wrist cuffs Which part of a quality management program involves the use of external controls? How should you wash your hands after removing gloves? - ANSWER Wash your hands with soap for at least 20 seconds. Which part of a quality management program involves the use of external controls? - ANSWER Examination What is the proper concentration of sodium hypochlorite needed to disinfect your bench station? - ANSWER 1:10 What is the best procedure for removing gloves when leaving the laboratory? - ANSWER Take gloves off and wash hands. How should you pack specimens for transport? - ANSWER Place them in a metal leak-proof box upright in a sealed internal container or bag. The Centers for Disease Control and Prevention developed standard precautions using the assumption that: - ANSWER all patients are potentially infected or carriers of transmittable organisms, so appropriate precautions need to be followed. Where should you dispose of blood-soaked gauze pads? - ANSWER Red biohazard bag Which series of dilutions would be best in order to make a 1:3000 dilution? - ANSWER 1:5, 1:6, 1:100 An antibody titer is defined as the reciprocal of the - ANSWER Last serial dilution tube in which a positive reaction is still visible How should a 1:50 dilution be made if the final volume needed is 10mL - ANSWER 0.2mL serum and 9.8mL of diluent A new assay is used to test 120 samples from patients with a clinically confirmed diagnosis of the relevant infection and 50 samples from healthy control subjects. The test results were positive for 90 of the infected and 10 of the healthy controls. If assay was used to test a population of 240 infected patients and 50 healthy controls, which assay parameter would increase? - ANSWER Positive predicted value If complement interferes with test results, the serum sample should be - ANSWER Heated to 56 C for 30 minutes The concentration of a solution is reduced by adding - ANSWER Diluent On a serial dilution with the following tubes set up, 1:2, 1:4, 1:8, 1:16, 1:32, & 1:64, there is no visible agglutination in the 1:64 tube. What is the titer? - ANSWER 32 If there will be an unavoidable 4-hour delay before a serum sample can be tested, the sample should be - ANSWER Refrigerated between 2C and 8C The probability that a person with a positive screening test actually has the disease screened for is called - ANSWER Positive predictive value A patients serum must be added to a series of test tubes, but a different volume of serum must be added to each tube. If a single pipette is used, what kind is it? - ANSWER Graduated To prepare 70mL of a 10% solution of acetic acid, how much acetic acid is needed? - ANSWER 7mL What type of pipette must be blown own to deliver exact volume of liquid? - ANSWER Serological If 0.9mL of saline is added to 0.1mL of serum what does the 0.9mL represent? - ANSWER The diluent If you want to make a 4mL of a 1:20 dilution, how much serum would be needed? - ANSWER 0.2mL A blowout pipette would be labeled - ANSWER TC Serology is the study of - ANSWER The liquid components in the blood, especially antibodies. A new assay is used to test 120 samples from patients with a clinically confirmed diagnosis of the relevant infection and 50 samples from healthy control subjects. The test results were positive for 90 of the infected and 10 of the healthy controls. Calculate the positive predictive value of the assay - ANSWER 90% Identify the characteristic of associated with noncompetitive enzyme immunoassays - ANSWER They are less sensitive than agglutination reactions A good enzyme for use in an immunoassay should have a - ANSWER High substrate conversion rate Quenching the signal emitted by the label is of particular concern in - ANSWER Chemiluminescent immunoassays The standard method for detecting antinuclear antibodies (in certain autoimmune diseases) is - ANSWER Indirect immunofluorescence Which compound would be an appropriate label in a chemiluminescent assay? - ANSWER Ruthenium derivative In which of the following testing situations is there a direct relationship between the amount of bound label and he amount of patient antigen present? - ANSWER Noncompetitive enzyme immunoassay using a second labeled antibody 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 - ANSWER directly proportional A tissue section is fixed to a microscope slide, then incubated with a fluorescently labeled antibody that binds to an antigen expressed by cells in that tissue. The preparation is then washed and inspected with a fluorescent microscope. This technique is called - ANSWER Direct immunofluorescence .