Collection of blood from healthy subjects for research must be performed under an IRB approved protocol. The PI would be responsible for determining the guidelines for the collections and writing that into the protocol. Sometimes, it's just as simple as saying that the FDA/ AABB requirements for allogeneic donation will be met. Or they may have a special need for other criteria. All that needs to be spelled out. Google 'human research subjects'- you'll get a boatload of information. Oh, and yes, they can be compensated for their time and trouble...