What's the best gift you can give? To the millions of people whose lives have been saved by complete strangers, the answer would be simple: blood. But what exactly happens when blood has been donated, and how do we know it is safe? We chat to Dr Richard Mayne from Oxford's Experimental Medicine Division about genomics, Next-Generation Sequencing, blood screening (...and Star Trek).

Could you be a blood-donating hero? Blood stocks are currently critically low, with the NHS Blood and Transplant (NHSBT) group in urgent need of new donors. Click here, and you'll be on your way to saving lives: https://www.blood.co.uk/news-and-campaigns/campaigns/blood-donor-appeal/