🩺 Q543: A laboratory result for a quality control (QC) level is 3.5 standard deviations from the mean. According to Westgard rules, which rule is violated?
Anonymous Quiz
4%
A) 1-2s
70%
B) 1-3s
22%
C) 2-2s
4%
D) R-4s
🩺 Q544: A patient sample is collected in a gel-barrier tube but is not centrifuged for 4 hours. How will this delay most likely affect the serum potassium concentration?
Anonymous Quiz
7%
A) Falsely decreased due to potassium uptake by RBCs
50%
B) Falsely increased due to potassium leakage from RBCs
27%
C) No change, as the gel barrier prevents interaction
17%
D) Increased due to hemolysis from prolonged clot formation
🩺 Q545: A laboratory technician needs to separate plasma from cells. What is the primary factor that determines the sedimentation rate in a centrifuge?
Anonymous Quiz
0%
A) The color of the tube cap
72%
B) The square of the rotor speed (RPM)
28%
C) The distance from the center of rotation
0%
D) The ambient temperature
🩺 Q546: Which type of microscopy is specifically indicated for the identification of birefringent crystals like uric acid in synovial fluid?
Anonymous Quiz
28%
A) Phase-contrast microscopy
33%
B) Dark-field microscopy
33%
C) Polarized light microscopy
6%
D) Fluorescence microscopy
🩺 Q547: What is the primary function of the 'sample probe' in a random-access automated analyzer?
Anonymous Quiz
0%
A) To mix the reagents
79%
B) To aspirate and dispense exact volumes of specimen
21%
C) To read the barcode on the specimen tube
0%
D) To incubate the reaction mixture
🩺 Q548: In a Westgard multi-rule system, what does the 1-3s rule indicate?
Anonymous Quiz
24%
A random error violation
76%
B) A systematic error violation
0%
C) A trend in the data
0%
D) A shift in the mean
🩺 Q549: According to the NFPA 704 system, what does the 'Yellow' diamond on a chemical label represent?
Anonymous Quiz
0%
A) Flammability
38%
B) Health hazard
46%
C) Instability/Reactivity
15%
D) Special hazard
🩺 Q550: A laboratory observes a 'shift' in quality control results for the last 6 days, where all values are on one side of the mean but within 2SD. What is the most likely cause?
Anonymous Quiz
13%
A) Random instrument fluctuation
80%
B) A change in reagent lot or calibrator lot
7%
C) An error in pipetting the control
0%
D) A sudden power surge
🩺 Q550: A laboratory observes a 'shift' in quality control results for the last 6 days, where all values are on one side of the mean but within 2SD. What is the most likely cause?
Anonymous Quiz
8%
A) Random instrument fluctuation
83%
B) A change in reagent lot or calibrator lot
8%
C) An error in pipetting the control
0%
D) A sudden power surge
🩺 Q551: In the event of a large chemical spill in the laboratory involving a corrosive acid, what is the first step?
Anonymous Quiz
8%
A) Neutralize the spill with a base
75%
B) Evacuate the area and alert personnel
8%
C) Absorb the spill with paper towels
8%
D) Clean the spill with water
🩺 Q552: What is the primary purpose of a 'Levey-Jennings' chart?
Anonymous Quiz
0%
A) To calculate patient reference ranges
100%
B) To track the performance of control materials over time
0%
C) To calibrate the analyzer
0%
D) To verify patient identity
🩺 Q553: When working with specimens potentially contaminated with bloodborne pathogens, which of the following is an example of an engineering control?
Anonymous Quiz
17%
A) Handwashing after glove removal
83%
B) Use of safety-engineered needle devices
0%
C) Wearing a lab coat
0%
D) Prohibiting eating in the lab
🩺 Q554: Which of the following parameters is used to calculate the Coefficient of Variation (CV)?
Anonymous Quiz
0%
A) Mean and Median
92%
B) Standard Deviation and Mean
0%
C) Range and Mode
8%
D) Variance and Variance of the mean
🩺 Q555: What does a 'Trend' in quality control data suggest?
Anonymous Quiz
0%
A sudden instrument failure
100%
B) A gradual deterioration of reagents or light source
0%
C) A clerical error in data entry
0%
D) A one-time pipetting error
🩺 Q556: According to OSHA standards, what information must be included in a Safety Data Sheet (SDS)?
Anonymous Quiz
0%
A) The price of the chemical
100%
B) Physical hazards and first-aid measures
0%
C) The expiration date of the chemical
0%
D) The supplier contact name only
🩺 Q557: [Hematology & Hemostasis Case (Series #3, Case #6)] Which anticoagulant is the gold standard for routine Prothrombin Time (PT) and APTT testing?
Anonymous Quiz
0%
A) K2-EDTA
17%
B) Lithium Heparin
83%
C) Sodium Citrate (3.2%, 0.109 M)
0%
D) Potassium Oxalate
🩺 Q558: [Hematology & Hemostasis Case (Series #4, Case #7)] In automated hematology analyzers, the Coulter impedance principle detects cells by measuring:
Anonymous Quiz
0%
A) Light scatter intensity at 90 degrees
91%
B) Electrical resistance change as non-conductive cells pass an aperture
0%
C) Fluorescence emission after nucleic acid staining
9%
D) Radiofrequency conductivity absorption
🩺 Q559: [Hematology & Hemostasis Case (Series #4, Case #8)] Which anticoagulant is the gold standard for routine Prothrombin Time (PT) and APTT testing?
Anonymous Quiz
0%
A) K2-EDTA
0%
B) Lithium Heparin
100%
C) Sodium Citrate (3.2%, 0.109 M)
0%
D) Potassium Oxalate
🩺 Q560: [Hematology & Hemostasis Case (Series #5, Case #9)] In automated hematology analyzers, the Coulter impedance principle detects cells by measuring:
Anonymous Quiz
0%
A) Light scatter intensity at 90 degrees
100%
B) Electrical resistance change as non-conductive cells pass an aperture
0%
C) Fluorescence emission after nucleic acid staining
0%
D) Radiofrequency conductivity absorption
🩺 Q561: [Hematology & Hemostasis Case (Series #5, Case #10)] Which anticoagulant is the gold standard for routine Prothrombin Time (PT) and APTT testing?
Anonymous Quiz
0%
A) K2-EDTA
0%
B) Lithium Heparin
100%
C) Sodium Citrate (3.2%, 0.109 M)
0%
D) Potassium Oxalate