 A vampire's bite is not enough to turn a human into a vampire; the human, when near death, must drink the sire's blood or have vampire blood in his or her system at the moment of death.The process of vampirization also affects their genetics, causing their DNA to be fundamentally altered to suit their bodies' new state.This makes genetic testing between vampires and their human relatives impossible unless the vampire has a sample of their own human DNA from before they were turned, such as a lock of hair.