CABT Laboratory Equipment 2 — Questions and Answers
Question 1: Which type of centrifuge is specifically designed to separate blood components by spinning at low speeds (400-1200 RPM)?
- Microcentrifuge
- Ultracentrifuge
- Blood bank centrifuge (Correct answer)
- Refrigerated centrifuge
Correct answer: Blood bank centrifuge
Blood bank centrifuges operate at low speeds optimized for separating red cells, plasma, and platelets without damaging fragile blood components.
Question 2: A biomedical technician notices a pH meter gives inconsistent readings. The FIRST corrective step should be:
- Replace the electrode
- Recalibrate with fresh buffer solutions (Correct answer)
- Replace the meter entirely
- Increase the temperature compensation setting
Correct answer: Recalibrate with fresh buffer solutions
Recalibration with fresh, properly prepared buffer solutions is always the first step when troubleshooting inconsistent pH meter readings.
Question 3: What is the primary function of a laminar flow hood in a clinical laboratory?
- To sterilize instruments with UV light
- To provide a sterile work environment by directing HEPA-filtered air over the work surface (Correct answer)
- To provide negative pressure containment for hazardous pathogens
- To maintain specimen temperature during processing
Correct answer: To provide a sterile work environment by directing HEPA-filtered air over the work surface
Laminar flow hoods direct HEPA-filtered air in a unidirectional flow over the work surface to protect samples and cultures from contamination.
Question 4: A hematology analyzer flags a specimen with clogged apertures. Which maintenance procedure should be performed?
- Run a bleach solution followed by rinse cycles (Correct answer)
- Replace the aperture tube immediately
- Run a dilute saline flush only
- Power cycle the instrument
Correct answer: Run a bleach solution followed by rinse cycles
Running a bleach (sodium hypochlorite) cleaning solution followed by rinse cycles dissolves protein and fibrin clogs in aperture tubes.
Question 5: Which pipette type delivers the most accurate volumes for analytical chemistry procedures?
- Pasteur pipette
- Serological pipette
- Volumetric pipette (Correct answer)
- Micropipette with disposable tip
Correct answer: Volumetric pipette
Volumetric pipettes are calibrated to deliver a single, precise volume (TC or TD) and are the most accurate for analytical work.
Question 6: When performing preventive maintenance on an autoclave, which parameter is most critical to verify?
- Chamber temperature distribution and sterilization cycle time (Correct answer)
- Water reservoir level only
- External surface cleanliness
- Door seal color
Correct answer: Chamber temperature distribution and sterilization cycle time
Temperature distribution across the chamber and accurate cycle timing are critical to confirm that sterilization parameters are consistently met.
Question 7: A refrigerated specimen storage unit in the lab reads 8°C instead of the required 2-8°C upper limit alarm. What should the technician do FIRST?
- Immediately move all specimens to another unit and report the excursion (Correct answer)
- Adjust the thermostat and continue using it
- Discard all specimens
- Turn off the alarm
Correct answer: Immediately move all specimens to another unit and report the excursion
Specimens must be relocated to a qualified unit immediately, and the temperature excursion must be documented and reported per laboratory protocol.
CABT Laboratory Equipment 2
Which type of centrifuge is specifically designed to separate blood components by spinning at low speeds (400-1200 RPM)?