Question to the Department of Health and Social Care:

To ask Her Majesty's Government what is their current estimate for (1) the proportion of polymerase chain reaction tests for COVID-19 that are false positives, and (2) the number of cycles that such tests now go through; and whether they will place details of the research that supports the estimate of false positives and the decision on the number of cycles to be used in the Library of the House.

The current sensitivity of our polymerase chain reaction (PCR) tests for COVID-19 at our lighthouse laboratories is over 99%. It is not possible to provide a precise figure for the number of cycles PCR tests for COVID-19 go through as this will vary from test to test based on a variety of different factors. All manufacturers of PCR tests for COVID-19 must meet the requirements of our validation process to ensure the accuracy of their tests. These requirements, National technical validation process for manufacturers of SARS-CoV-2 (COVID-19) tests, are published online at GOV.UK.