Calibrators and controls are essential components of quality assurance processes in laboratory testing, ensuring the accuracy and reliability of analytical measurements.
Calibrators are standardized materials with known concentrations of analytes, used to establish a calibration curve or reference points on an instrument’s measurement scale. They serve as a reference against which the measurements of unknown samples are compared, allowing for accurate quantification of analytes. Calibrators are typically prepared from pure substances or certified reference materials and are available in various concentrations to cover the range of interest for a particular assay. During calibration, the instrument’s response to each calibrator concentration is measured, and a mathematical relationship (calibration curve) between concentration and response is established. This curve is then used to determine the concentration of analytes in unknown samples based on their measured responses.
Controls, on the other hand, are samples with known concentrations of analytes that are analyzed alongside patient samples to monitor the precision and accuracy of laboratory assays over time. Controls help detect and correct systematic errors or variations in test results, ensuring the reliability of test results. Controls are typically run at regular intervals during testing, and their results are compared to predefined target values or ranges known as control limits. If the control results fall within acceptable limits, it indicates that the assay is performing within specifications. However, if control results fall outside the expected range, it signals the need for investigation and corrective action to identify and rectify the underlying issue, such as instrument malfunction, reagent degradation, or operator error.