Quality & Safety Flashcards
7 cards from real MLS practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Quality & Safety flashcards as text
A method validation study compares a new analyzer to a reference method using 40 patient samples. Which statistical analysis is used to assess proportional and constant bias?
Answer: Passing-Bablok or Deming regression
Passing-Bablok and Deming regression are used in method comparison studies to detect proportional and constant systematic errors between two methods.
What is the purpose of running a blank in photometric assays?
Answer: To zero the instrument and eliminate background absorbance
The reagent blank zeroes the spectrophotometer to account for background absorbance from reagents, isolating the analyte's contribution.
A laboratory's glucose linearity study shows acceptable results from 10–500 mg/dL but not above. What should be done for patient samples with glucose above 500 mg/dL?
Answer: Dilute the sample and multiply the result by the dilution factor
Samples exceeding the analytical measurement range must be diluted; results are then multiplied by the dilution factor to report an accurate value.
The GHS (Globally Harmonized System) label on a chemical container includes a pictogram of a flame over a circle. This indicates the substance is:
Answer: An oxidizer
The GHS flame-over-circle pictogram specifically denotes oxidizing substances, which can intensify fires or cause spontaneous combustion.
Which of the following is an example of a pre-analytical error affecting laboratory results?
Answer: Hemolysis due to traumatic venipuncture
Hemolysis from traumatic venipuncture is a pre-analytical error occurring before the sample reaches the analyzer, potentially falsely elevating potassium and LDH.
A laboratory technologist notices the QC for troponin has been trending upward over 10 days without violating a Westgard rejection rule. This pattern most likely indicates:
Answer: Systematic shift due to reagent or calibration change
A gradual upward trend in QC data often signals systematic drift, typically caused by reagent deterioration, calibrator instability, or instrument maintenance issues.
Under CLIA regulations, how often must laboratories perform and document calibration verification for quantitative tests?
Answer: Every 6 months
CLIA requires calibration verification at least every 6 months, when reagent lots change, after major instrument maintenance, and when QC is out of range.