Laboratory Equipment Flashcards
7 cards from real CABT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Laboratory Equipment flashcards as text
What is the primary purpose of a Coulter counter (impedance-based cell counter) in a clinical lab?
Answer: Counting and sizing cells by electrical impedance as they pass through an aperture
A Coulter counter counts and measures cell size by detecting changes in electrical impedance as individual cells pass through a small aperture in an electrolyte solution.
Which type of pipette should be used to transfer 0.05 mL of serum for a clinical chemistry assay?
Answer: 50 µL micropipette
A 50 µL (0.05 mL) micropipette with a calibrated disposable tip provides the accuracy required for small-volume serum transfers in clinical chemistry.
During routine maintenance of a microscope, immersion oil is found on the 40× dry objective lens. The correct cleaning agent is:
Answer: Lens paper moistened with lens cleaner or xylene substitute
Lens paper moistened with a lens cleaning solution or xylene substitute safely removes immersion oil without damaging optical coatings on dry objectives.
What does 'CV%' (coefficient of variation) measure when validating laboratory equipment precision?
Answer: The percentage of random variability relative to the mean across repeated measurements
CV% = (standard deviation / mean) × 100, expressing random variability as a percentage of the mean to assess instrument precision.
A gas chromatograph (GC) used in toxicology shows baseline noise. Which component is most likely responsible?
Answer: Detector or detector contamination
Detector contamination or detector malfunction is the most common cause of elevated baseline noise in gas chromatography systems.
Which safety practice is required when transporting a compressed gas cylinder in a hospital laboratory?
Answer: Secure it upright in a wheeled cart with a chain or strap
Compressed gas cylinders must be secured upright in a wheeled cart with a restraining chain or strap to prevent tipping and valve damage during transport.
In an automated immunoassay analyzer, what is the function of the 'wash buffer' step?
Answer: To remove unbound antibodies or conjugates, reducing background signal
Wash buffer steps remove unbound reactants between incubation phases, which is essential for minimizing background and achieving specific, accurate immunoassay results.