COVID-19 - laboratory testing frequently asked questions

Publication Date: 21 December 2020

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This FAQ answers the following questions:

  • What is SARS-CoV-2?
  • What tests are available for SARS-CoV-2?
  • Where are tests performed?
  • What is PCR?
  • What is a Ct value?
  • How do you know that the RT-PCR test for SARS-CoV-2 is accurate?
  • What quality control processes are in place for PCR?
  • How many PCR tests for SARS-CoV-2 can be performed in Scotland?
  • What do sensitivity and specificity values of a test describe?​
  • What is the sensitivity/specificity of the Scottish PCR test?
  • If a test isn’t 100% sensitive/specific, does this mean we cannot rely on the results it provides?
  • What is the difference between PCR testing and antigen testing?
  • How reliable are tests performed outside of NHS services?
  • Where can I learn more about SARS-COV-2?

Resource information

Public Health Scotland
Publication type:
Guideline and Guidance


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