This is not directly related, but I can't seem to get an answer from anywhere... The self tests that are available at MTR ( saliva tests ) and then submitted at a local health center - does anyone know how long they are good to use for? I got 4 from the MTR station last week... I'm due to submit another sample next week - will these tests still be ok for then, or do I need to get another test kit closer to the time?