On 1 Feb 2021, during the COVID-19 pandemic the Health and Social Care Secretary, Matt Hancock, said 'our global leadership in genomic sequencing has helped us to spot new variants here in the UK, and quickly alert the rest of the world'. Another example of government spin? This series of 5 lectures will describe what genomic sequencing is, how it works, and reveal the Cambridge pub where 'NextGen' sequencing was born. It will address some of its applications to understanding genetic diseases and cancer as well as its role in fighting COVID-19, and on the way I'll explain what a PCR test is. The course has been extended from 3 weeks in 2021 to cover the material at a somewhat slower pace with additional material on applications such as gene therapy.