Once you’re cleared, your phlebotomist will prepare you for the actual donation process. First, they will clean your skin with an anti-infective agent like iodine before attempting to find a large arm vein close to the surface of your skin. This often (but not always) ends up being the vein on the inside of the elbow. Next, the phlebotomist will insert a hollow needle through the skin and into the vein before attaching the needle to medical tubing, and whatever collection method is being used for your donation.