What should you know about saliva PCR test?

PCR testing amplifies small amounts of genetic material, which can make it useful when a sample contains only a limited amount of virus. A positive result means the target genetic material was detected; it should be interpreted with your symptoms, exposure history and the test instructions. A negative result means the target was not detected in that sample, but it may not exclude infection if testing was done very early, the sample was poor, or symptoms change.

Saliva collection is non-invasive, but eating, drinking, smoking, chewing gum or using mouthwash shortly beforehand can affect collection instructions. Follow the laboratory or clinic directions exactly, including how much saliva to provide and how to label or return the sample.

Check whether your test is processed by a laboratory and when results are expected. Until a positive result is clarified, reduce close contact with others if you have respiratory symptoms, wash your hands and follow current local health advice. A clinician can explain whether you need repeat testing, further assessment or treatment based on your symptoms and risk factors.

Do not compare a saliva PCR result directly with a rapid antigen test result: they detect different signals and have different collection and processing requirements. Keep the result message available when speaking with a healthcare professional.

Seek urgent medical help for severe difficulty breathing, persistent chest pain, new confusion, fainting, blue or grey lips, or an inability to stay awake. Contact a clinician promptly if fever or breathing symptoms are worsening, you cannot keep fluids down, or you have a condition or treatment that weakens immunity.

Ask which infection the test targets, whether your sample met collection requirements, how the result fits your symptoms, and whether another test or follow-up is needed.