It is seventeen, and for those who dont know how it is done here goes. Fist they prick your finger, not a lot just slightly and squeeze out some blood a put it in a tube filled with a liquid, this is just to see if it is OK to take. Then they lie you on a bed and use one of those arm bandage things to make a visible vein. Next they take the needle a put it in to the vein, you cant feel the sharpness of it going in, just a slighty stinging sensation for a couple of seconds. They then take your blood. Then they ask you to lie down for 10 mins so you dont faint and then my personal favourite part they give you loads of biscuits and drinks to have.
A bit of advice:
-You are allowed to pull out at any point and you wont be the only one to do so, alot of people's nerves get to them.
-It a good meal before and after to keepup your strength
-Dont do much excercise or strenuous activity after