{"id":9612,"date":"2025-05-20T04:03:32","date_gmt":"2025-05-20T01:03:32","guid":{"rendered":"https:\/\/medilab.km.ua\/?p=9612"},"modified":"2026-05-27T12:02:58","modified_gmt":"2026-05-27T09:02:58","slug":"sensitivity-of-plr-tests-in-clinical-practice-to-borderline-values-and-erroneous-results","status":"publish","type":"post","link":"https:\/\/medilab.km.ua\/en\/sensitivity-of-plr-tests-in-clinical-practice-to-borderline-values-and-erroneous-results\/","title":{"rendered":"Sensitivity of PCR tests in clinical practice: from cutoff values to false positives"},"content":{"rendered":"

In laboratory diagnostics of infectious diseases, PCR has become the gold standard. But even the most modern tests do not always guarantee an error-free result. The key factor determining their effectiveness is sensitivity<\/strong>, i.e. the ability to detect a minimal amount of genetic material of the pathogen. In this article, we will consider what high or low sensitivity means, how it is determined, why it can vary in real conditions, and how it affects clinical decisions.<\/p>\n

Determination of sensitivity in PCR<\/h2>\n

The sensitivity of a PCR test refers to the smallest number of copies of a pathogen's DNA or RNA that the method can detect with high confidence. This value is measured in copies per microliter or in log\u2081\u2080 units (e.g., 10\u00b2 copies\/\u03bcL).<\/p>\n

How is sensitivity determined: analytical and clinical approaches<\/h2>\n

In laboratory conditions analytical sensitivity<\/strong> is verified by serial dilution of the control material. For example, if the test detects SARS-CoV-2 in 95% cases at 200 RNA copies\/\u00b5l, the LoD (limit of detection) is considered to be this number.<\/p>\n

Clinical sensitivity<\/strong> \u2014 is the percentage of infected patients who test positive. Additional factors come into play here: the quality of sample collection, stage of the disease, and transportation conditions.<\/p>\n

When high sensitivity is critical<\/h2>\n