The one I had was from the University of London in conjunction with the NHS, got a test kit in the post, consists of taking your blood with a small lancet and placing a drop on a small piece of plastic and then applying a solution to the kit. It then gives a reading to indicate if you have the antibodies, it's very similar looking to a pregnancy test kit. There is also a quite lengthy on line questionnaire to complete.Had a letter asking me to take part in antibody test survey this morning. It’s clear that it’s to show how many may have had COVID, I presume if you have tested positive it will ask for details during the registration so they also get data on how long antibodies last?