🅰️🅱️🅾️±

#blood group system #abo rh #blood typing #blood antigens #rhesus factor

🅰️🅱️🆎🅾️💉

#ABO system #AB type #blood group system #transfusion #blood donation #antigens

🩸🚫⚛️

#rh null #absence of antigens #blood group system #zero antigens #rare blood type #missing antigens