I have totally donated 2 litres of blood so far.In one cse it was 1 litre.This should have been important,as the relatives of the receiver,respoded favourably,with one of their own.
I do not know whether it saved the life of the recepient.
I donated it once. To my friend who was sufferin from cancer. But he was not saved. It was disappointin. But wen i got the opportunity for the second time i cud not do it as i was havin cold. Hope to do it again.