What is donated blood tested for? A comprehensive guide.

What is donated blood tested for? A comprehensive guide.

When you donate blood, it goes through a thorough testing process before being used in transfusions. This testing is important to ensure that the blood is safe for the recipient and to prevent the spread of infectious diseases. In this article, we will take a look at the different tests that donated blood undergoes.

Test for Blood Type

One of the first tests that is done on donated blood is a test for blood type. This is important because blood that is incompatible with the recipient’s blood type can cause serious reactions, such as hemolytic transfusion reactions.

Infectious Disease Testing

Donated blood is tested for various infectious diseases to ensure that it is safe for transfusion. Some of the tests that are done include:

  • Human Immunodeficiency Virus (HIV): This virus attacks the immune system and can lead to AIDS.
  • Hepatitis B and C: These viruses can cause liver damage and lead to liver cancer.
  • West Nile Virus (WNV): This virus is spread by mosquitoes and can cause fever, headache, and other symptoms.
  • Syphilis: This bacterial infection is spread through sexual contact and can cause serious complications if left untreated.
  • Chagas Disease: This parasitic infection is spread by insects and can cause heart and digestive system damage.

If any of these tests come back positive, the blood is discarded and the donor is notified.

Other Tests

In addition to blood typing and infectious disease testing, donated blood also undergoes the following tests:

Antibody Screening

Antibody screening tests are done to detect the presence of antibodies in the donor’s blood. Antibodies are proteins produced by the immune system in response to foreign substances. If antibodies are detected, further testing may be done to identify the specific type of antibody.

Nucleic Acid Testing (NAT)

NAT is a sensitive test that is used to detect the genetic material of viruses in the blood. This test is used to detect viruses that may not be detected by other tests, such as HIV or hepatitis C.

Bacterial Testing

Donated blood is also tested for bacterial contamination. Bacterial infections can be serious, especially in individuals with weakened immune systems.


After testing is complete, blood may be irradiated to prevent graft-versus-host disease (GVHD). GVHD occurs when the donor’s immune cells attack the recipient’s cells, which can be life-threatening.


Donating blood is a selfless act that can save lives. When you donate blood, you can rest assured that it undergoes a thorough testing process to ensure that it is safe for transfusion. The tests that donated blood undergoes include blood typing, infectious disease testing, antibody screening, NAT, bacterial testing, and irradiation.

Frequently Asked Questions

  • What happens if donated blood tests positive for an infectious disease? If donated blood tests positive for an infectious disease, it is discarded and the donor is notified.
  • Can donated blood be tested for all infectious diseases? No, some infectious diseases may not be detectable by current testing methods.
  • What is graft-versus-host disease? Graft-versus-host disease occurs when the immune cells in the donated blood attack the recipient’s cells.
  • How long does it take for donated blood to be tested? It can take several days for donated blood to undergo all the necessary tests.
  • How often should I donate blood? You can donate blood every 56 days.


  • AABB.org. (2021). Blood Donation Testing. [online] Available at: https://www.aabb.org/tm/blood-donation/donation-process/testing/ [Accessed 6 Oct. 2021].
  • American Red Cross. (2021). Blood Screening: What Are They Looking For? [online] Available at: https://www.redcrossblood.org/donate-blood/blood-donation-process/what-happens-to-donated-blood/blood-screening.html [Accessed 6 Oct. 2021].
  • Mayo Clinic. (2021). Blood donation. [online] Available at: https://www.mayoclinic.org/tests-procedures/blood-donation/about/pac-20385144 [Accessed 6 Oct. 2021].

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