Occasionally, a doctor will urge a patient to deposit his own blood weeks before surgery (preoperative autologous blood donation, or PAD) so that if the need arises, he could transfuse the patient with his own stored blood. However, such collecting, storing, and transfusing of blood directly contradicts what is said in Leviticus and Deuteronomy. Blood is not to be stored; it is to be poured out—returned to God, as it were. Granted, the Mosaic Law is not in force now. Nevertheless, Jehovah’s Witnesses respect the principles God included in it, and they are determined to ‘abstain from blood.’ Hence, we do not donate blood, nor do we store for transfusion our blood that should be ‘poured out.’ That practice conflicts with God’s law.
An yet they will accept fractions of blood that was drawn out of someone's arm, stored, separated and stored again and all the while beleive they are abstaining from blood.
They let someone else donate blood (supposedly breakig Gods law) but accept fractions of that blood and let the donor take the fall for having donated it.