Which statement distinguishes calibrators from controls?

• A. Calibrators provide known values to establish a calibration curve.
• B. Calibrators provide known values to establish a calibration curve; controls are samples with known values used to verify assay accuracy on each run.
• C. Calibrators are used to verify instrument cleanliness; controls calibrate the instrument.
• D. Calibrators and controls are interchangeable.

Answer: (B)

Calibrators establish the measurement scale for an assay. They are materials with known values (such as concentrations) that are used to generate a calibration curve, which relates the instrument signal to the amount of analyte. Once this curve is set, unknown samples can be quantified by matching their signals to the curve.

Controls, in contrast, are samples with known values that are run with each batch to verify that the assay is performing accurately in that specific run. They help detect drift, reagent problems, or instrument issues and ensure the results for that run are reliable.

So the best statement is that calibrators provide known values to establish a calibration curve, while controls are samples with known values used to verify assay accuracy on each run.