Rh factor

The Rh factor was identified as a crucial component in preventing erythroblastosis fetalis in newborns, where it was missing in Rh-negative mothers with Rh-positive fetuses. Named after Rhesus monkeys used as experimental animals, its discovery allowed for routine testing and better management of blood transfusions.
 Philip Levine United States 1939 Rh factor

The Rh factor was identified as a crucial component in preventing erythroblastosis fetalis in newborns, where it was missing in Rh-negative mothers with Rh-positive fetuses. Named after Rhesus monkeys used as experimental animals, its discovery allowed for routine testing and better management of blood transfusions.