Everything You Ever Wanted to Know About Blood Banking, but didn't have a clue, and things I would like to tell Nurses

Telling someone I work in a blood bank automatically results in, "Wow, I have a really rare blood type!" or "Can you tell me what my blood type is?".

Everyone wants to know their blood type. You might be surprised to know that no blood banker worth a darn is going to accept your stated blood type. We just smile and say "that's interesting!" or words to that effect. The only time we will accept your blood type is when we draw your blood ourselves and get it down to our little work station and type those cells ourselves. And then we'll only trust it for three days.

Sporting a "rare" blood type is NOT a good thing. When we actually do find a rare blood type, we have to work much harder to find compatible blood for you. If you are bleeding to death, you may continue to do so until we find a donor with a matching rare blood type. This is not an easy thing to do and I have encountered truly rare blood types that take days to find a match. Yes, days! If you are laying there with a brain starving for oxygen carrying red blood cells, then you want to have the most common blood type there is, trust me.

People with rare blood types should NEVER get in a car wreck or use a chain saw. If they rupture a major artery, they are going to die before compatible blood can be found. Giving them common blood that is not matched to their antibodies will kill them just as dead.

Calculating from the chart above the "rare" blood type is Group AB, Rh - (Negative) in a person of Asian descent.

But wait, there's more!

Blood types are determined by Antigens. If you have the A antigen present on your blood cells, then you are a Group A. If you have the B antigen, then you are a Group B. If you have both antigens present, then you are Group AB. If you have neither antigen present, then you are Group O.

Your Rh antigen is either present (positive) or absent (negative).

So, two different kinds of antigens are needed to determine your Group (ABO) and your Type (positive or negative).

Now, unbeknown to the vast majority of humans, you may also carry around on your cells some other interesting antigens. These antigens have letter names or the names of scientists that discovered them. A partial list includes:

• C and c - part of the Rh system, these antigens come in genetic pairs
• E and e
• Fya and Fyb - also called the Duffy antigens
  
• Jka and Jkb - also called the Kidd antigens
• Lua and Lub - also called the Lutheran antigens
• M and N
• P1
• S and s
• V - also called the Vell antigen

In the case of super rare blood, a patient will have Antibodies to one or more these antigens. A blood banker must find a reciprocal "match" for these patients. 

Once a patient forms one or more antibodies to these antigens, they cannot receive blood that has the antigen again or their antibodies will attack those antigen carrying cells and destroy them. This is known as a Transfusion Reaction and can be deadly.

The easiest way to crossmatch blood is to physically mix the patient's plasma with the donor's cells. The theory is that if a patient has an antibody, it will react in the test tubes and we will know that this blood should not be given. If no reaction is observed, we assume it is safe blood to give.

This is very simplistic of course, and the human body does some strange things that may or may not happen in a test tube. We try to mimic phases from the body with our test tubes, but it is still not 100% guaranteed to be safe.

To date, no one has discovered an artificial substitute for real human blood. Science has a way to go yet to be able to build a working red cell molecule. We're getting very close now. I have no doubt that in the near future, perhaps within the next 20 years, we will have a viable substitute and I will be out of a job.

1. Human blood really does come from humans and can't be magically bagged up out of thin air. When we say it takes 45 minutes to get blood ready for a transfusion, we mean that. No, we can't get it ready any faster.
2. Fresh Frozen Plasma is FROZEN! We have to thaw it out before it can be transfused. We can't change the laws of physics and give it to you instantly.
3. Every time you call to ask how much longer until things are "ready" means a delay of however much time it takes for us to explain that to you, again.
4. Blood Banking is governed by some very strict laws and safety protocols. Obey them!
5. There are procedures in place for giving blood in emergency situations. Learn these procedures ahead of time, don't wait for an emergency!