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
The Westgard 2-2s rule is triggered when:
Answer: Two consecutive controls exceed the mean by 2 SD in the same direction
The 2-2s warning rule is triggered when two consecutive QC results exceed ±2 SD on the same side, suggesting systematic error.
Which of the following actions is MOST appropriate when a QC result violates a rejection rule before reporting patient results?
Answer: Hold patient results, identify the problem, and repeat QC
Patient results must be held until the QC problem is identified and corrective action is verified by repeat QC.
A laboratory notices that serum potassium results are falsely elevated on specimens left at room temperature for several hours. This is due to:
Answer: Leakage of potassium from red blood cells
Red blood cells contain high intracellular potassium; prolonged contact with serum at room temperature causes leakage, elevating results.
The term 'analytical sensitivity' in laboratory testing refers to:
Answer: The lowest detectable concentration of an analyte
Analytical sensitivity is the lowest analyte concentration reliably detected by the assay, also called the limit of detection.
A laboratory wants to verify the manufacturer's claimed reference interval for a new analyzer. The minimum number of reference samples recommended by CLSI is:
Answer: 20
CLSI EP28-A3c recommends a minimum of 20 reference individuals to verify a manufacturer's claimed reference interval.
Which of the following is a characteristic of random error?
Answer: It is unpredictable and affects precision
Random errors are unpredictable and cause scatter around the mean, degrading precision without a consistent directional bias.
Which laboratory document defines the specific steps for performing a test, including specimen requirements, reagents, and result interpretation?
Answer: Standard operating procedure (SOP)
A standard operating procedure (SOP) provides detailed, step-by-step instructions for performing a specific laboratory test.