My day of testing was very interesting, but a bit exhausting. It started at 7:15 am. They gave me a wrist band and a schedule. Everyone at the hospital knew I was a potential donor when they saw my wristband, so they were very welcoming and helpful throughout the day. They put a butterfly IV in my arm that would stay in all day. My first test was glofil in nuclear medicine (not everyone has this and I believe this is the only reason for the daylong IV), this involved many blood draws at specific intervals. Then I proceeded to another department for my chest Xray, then another department for an EKG, then to the lab for urine and LOTS of blood draws, then I met the coordinator, social worker, and surgeon who gave me a brief exam of my abdomen, thyroid, and ankles(?) - wished I knew I'd be taking my socks off, I'd have gotten a pedi-, then returned to nuclear medicine to finish the glofil blood draws, although I had breakfast before I arrived at the hospital, I had to fast for 4 hours prior to my CT scan, which was the final test of the day. I arrived for my CT ahead of schedule and got out of the hospital about a half hour earlier than expected at 1:00 - at which time I was quite hungry and tired. It was a very informative day, bring along any questions you have. It helps to have someone with you, but basically, that person will just be sitting in different waiting rooms all day. My husband came along and read books all day, but was able to meet the coordinator and surgeon and ask his own questions.
None of the tests were scary and everyone was nice. The only part that I found uncomfortable was the CT scan, mainly because I had never been injected with a dye before, so I didn't know what that would feel like. It didn't help that I was a little shakey from the blood draws and not eating. Also, that room was cold and you must lay with your arms over your head. I swear the AC vent was pointed directly at my sweaty, nervous armpits! lol. But it was not a big deal, just a warm feeling when the dye was injected. I thought for a moment that I peed on the table.

Best of luck to you.