Pathology

Blood Banking

Blood Types

According to the American Association of Blood Banks, distribution of blood types in the US is the following:

O Rh-positive 38 percent

A Rh-positive 34 percent

B RH-positive 9 percent

O Rh-negative 7 percent

A Rh-negative 6 percent

AB Rh-positive 3 percent

B Rh-negative 2 percent

AB Rh-negative 1 percent

What is blood banking?

Blood banking is the process that takes place in the laboratory to ensure that the donated blood or blood products are safe, before they are used in blood transfusions and other medical procedures. Blood banking includes typing the blood for transfusion and testing for infectious diseases.

Facts about blood banking:

According to the American Association of Blood Banks:

About 40,000 units of red blood cells are needed every day.

The number of blood units donated is about 14 million a year.

There are approximately eight million volunteer blood donors.

About four million patients receive transfusions of blood units each year.

Each unit of blood is broken down into components, such as red blood cells, plasma and platelets. One unit of whole blood, once its separated, may be transfused to several patients, each with different needs.

Annually, more than 23 million units of blood components are transfused.

Who are the blood donors?

Most blood donors are volunteers. However, sometimes a patient may want to donate blood a couple of weeks before undergoing surgery, so that his or her blood is available in case of a blood transfusion. Donating blood for yourself is called an autologous donation. Volunteer blood donors must pass certain criteria:

at least 17 years of age
in good health
weigh at least 110 pounds
pass the physical and health history exam given prior to donation

What tests are performed in blood banking?

A certain set of standard tests are performed in the laboratory once blood is donated, including:

ABO group (blood type)

Rh type (positive or negative)

any unexpected red blood cell antibodies that may cause problems in the recipient

evidence of donor infection with:
- hepatitis viruses B and C
- human immunodeficiency viruses (HIV) 1 and 2
- human T-lymphotropic viruses (HTLV) I and II
- syphilis

Each unit of blood may be separated into several components:

red blood cells - carry oxygen and are commonly used to treat anemia

platelets - help control bleeding and are used in the treatment of leukemia and other forms of cancer

granulocytes - sometimes used to fight infections

fresh frozen plasma - helps control bleeding due to low levels of some clotting factors

cryoprecipitated AHF - helps prevent clotting

other substances, such as albumin, immune globulins, and clotting factor concentrates

This page was last updated on: May 31, 2006.