With all assessment done, you need to talk to the blood bank. At this stage you must fix-up which blood bank will be coming and ensure that the blood bank is clear about your expectations.
You can use the following two letters as the starting point of your communication with the blood bank and then take it off further.
Letter to the Blood Bank
Second Letter
Please make sure that you are aware about the need for each of the requirement you are posing before the blood bank. This site has all answers for you.