What Is Laboratory Quality Control?
Quality control (QC) in a clinical laboratory refers to the processes used to verify that test systems are performing correctly and that the results they generate are reliable. Without QC, even the most sophisticated analyser can produce misleading data — and misleading data can lead to harmful clinical decisions.
At DLS we run both internal quality control (IQC) and participate in external quality assurance (EQA) schemes, ensuring our performance is benchmarked not just against our own historical data, but against other laboratories nationally.
Internal Quality Control
Every day, before patient samples are processed, our scientists analyse commercial control materials with known target values. These are run at multiple concentration levels — typically low, normal, and high — to check that the instrument responds accurately across the clinically relevant range. Results are plotted on Levey-Jennings charts, and runs are rejected when statistical rules are violated.
External Quality Assurance
Participation in external schemes means that DLS periodically receives samples from an independent body whose true values are unknown to us at the time of analysis. We test them as we would any patient sample and submit our results. The scheme then compares our performance against all participating laboratories. This external check catches biases that internal QC alone might miss.
Why This Matters for Patients
A laboratory that invests in quality control is one you can trust. When DLS reports a result, that number is the product of a verified, controlled analytical process. For the doctor making treatment decisions, and for the patient whose health depends on those decisions, that reliability is everything.