Polymerase chain reaction (PCR) use in the pathology lab differs from research-based PCR in two fundamental ways, namely quality and clinical expertise. These are essential to producing a clinical diagnosis supported by results from a range of tests performed by different branches of 'the pathology laboratory'. In a research lab, PCR results are often relied on to confirm experimental outcomes. Recognising these differences requires experience in a high-quality pathology lab setting to fully appreciate the absolute need for quality and its ubiquity. My experience The many words below are based on 32 years of experience in both research and routine labs, using PCR as a tool to answer a range of questions.