Laboratory Operations and QC Flashcards
7 cards from real Medical Laboratory Technician Exam 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 Operations and QC flashcards as text
A Levey-Jennings chart shows a series of 6 consecutive QC results trending upward across the mean. What rule does this violate?
Answer: 10-x rule
The 10-x rule is violated when 10 consecutive results fall on the same side of the mean or show a progressive trend.
Which of the following best describes 'precision' in laboratory testing?
Answer: Reproducibility of repeated measurements
Precision refers to the reproducibility or repeatability of results when the same sample is tested multiple times.
When performing a delta check, the laboratory compares a patient's current result to:
Answer: The previous result from the same patient
Delta checks compare a patient's current result to their previous result to detect specimen identification errors or abrupt clinical changes.
A reagent blank is used in spectrophotometry to:
Answer: Set 100% transmittance with the solvent and reagents only
A reagent blank zeroes out absorbance contributed by reagents alone so that only the analyte of interest is measured.
Which type of error causes all results to shift consistently in one direction from the true value?
Answer: Systematic error
Systematic error (bias) causes a consistent, directional deviation of all results from the true value.
The coefficient of variation (CV) is calculated as:
Answer: (SD / Mean) × 100
CV = (SD / Mean) × 100, expressing precision as a percentage relative to the mean.
CLIA mandates that proficiency testing samples must be tested:
Answer: Using the same routine workflow as patient samples
CLIA requires PT samples to be processed using the same routine methods and personnel used for patient samples to ensure validity.