Blood Type Compatibility Made Easy for Nursing, Nursing School, and NCLEX Review. There are four main blood type groups (A, B, AB, and O). When combined with Rh factor, this gives us the 8 main blood types. Which blood types are compatible to donate or receive blood? O is the universal donor, while AB is the universal recipient. #bloodtypes #bloodtypecompatibility #bloodtype #learnontiktok #longervideos #nursesarah #nursesoftiktok #nurse #nursetok #bloodcompatibility #nursingschool #nursjngstude