Calibration of Clinical Laboratory Analytes
Continuing Education Credits
Objectives
- Describe the relationship between analyzer response and analyte concentrations.
- Explain the difference between calibration, calibration verification, and linearity verification.
- Identify scenarios in which calibration or re-calibration of clinical assay is necessary.
- Correlate QC data in a Levey-Jennings plot with calibration issues.
- List troubleshooting strategies when experiencing a calibration and/or QC failure.
Course Outline
- Calibration Overview
- What is Calibration?
- What is Calibration?
- What is a Calibrator?
- Based on the assay response recorded by the red arrow for an unknown sample in the picture, provide the best estimate for the concentration that would be recorded.
- Calibrator Safety and Handling
- Why is Calibrator Analysis Important?
- When Are Calibrators Analyzed?
- How Many Calibrators Must Be Analyzed?
- When is Calibration Not Required?
- When would recalibration most likely be necessary?
- Calibrator Set Points
- Wait! How are Calibrators "Calibrated"?
- Evaluation of Calibrations and Troubleshooting Calibration Issues
- Calibration Evaluation
- Automated vs. Manual Calibration Evaluation
- Do Calibrations of Clinical Analytes Always Produce a "Linear" Response?
- What is the most concerning aspect regarding the calibration response curve in the image?
- Calibration Verification and Linearity
- What is Calibration Verification?
- What is Linearity Verification?
- What is Analytical Measurement Range Verification?
- True or False: A calibration curve with a low calibrator of 0.5 ng/mL and a high calibrator of 6500 ng/mL is used to quantify an unknown patient sample to produce a result of 1.2 ng/mL. If the calibration curve is accepted and all QC parameters pass, this result can be released to the patient chart.
- Troubleshooting Failures Which May Require Recalibration
- Identifying Assay Failures Using Plotted QC
- Potential Assay Drift
- Potential Assay Shift
- Complete Calibrator Swaps
- Incorrect Reagent Swaps
- Which scenario best aligns with what is observed in the QC trending data in the image?
- True or False: Both levels of QC on an analyzer have been running low for the past few analyses. New QC material from a different lot was analyzed, and it was still low. The original QC material was analyzed on a different analyzer in the laboratory and was near the expected mean for each level. With this data, it is likely that the original QC material analyzed is not compromised, and further tro
- Strategies for Mitigating Calibration Failures
- Troubleshooting Steps
- Attempting Fresh QC Analysis
- Attempting Fresh Calibrator Analysis and Recalibration
- Attempting New Reagents or Other Consumables
- Advanced Techniques
- Know When to Escalate Calibration Failures
- During troubleshooting of a failed QC check, the instrument and calibration appear normal. Which of the following is the most likely cause of the failure?
- References
- References
Additional Information
Level of Instruction: Intermediate
Intended Audience: Medical laboratory scientists, medical laboratory technicians, laboratory supervisors, and laboratory managers. This course is also appropriate for MLS and MLT students and pathology residents.
Author Information: Alec Saitman, PhD, DABCC (CC, TC) completed fellowship training in Clinical Chemistry and Toxicology in the Department of Pathology at the University of California, San Diego. Dr. Saitman is board certified by the American Board of Clinical Chemistry (ABCC) in Clinical Chemistry and Toxicological Chemistry. He is currently the Technical Director of the Core Laboratory at Providence Regional Laboratories in Portland, Oregon. His research focuses on the development of small molecule quantitation assays using mass spectrometry. He is particularly interested in establishing efficient production workflows in toxicology testing to meet the growing testing demands in his laboratory.
The author has no conflict of interest to disclose.
Reviewer Information:
Kevin Foley, PhD, MLS, DABCC is the director of Clinical Pathology for Kaiser Permanente Northwest. He has been in this position since 2009. After becoming a medical technologist, Kevin went on to earn a PhD in pharmacology. He then completed a fellowship in clinical chemistry. Kevin has also held full-time faculty positions at the University of Vermont, Northern Michigan University, and Mayo Clinic, Rochester.
Joshua J. Cannon, MS, MLS(ASCP)CMSHCM received his Bachelor of Science and Master of Science in Medical Laboratory Science from Thomas Jefferson University in Philadelphia, PA. He holds Medical Laboratory Scientist and Specialist in Hematology certifications through the ASCP Board of Certification. He was a professor at Thomas Jefferson University for seven years before transitioning into his current role as Education Developer at MediaLab by Vastian. His areas of expertise and professional passions include clinical hematology and interprofessional education.