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How is donated blood tested before it can be used for transfusion?

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Blood transfusion — blood transfusion Depiction of a direct blood transfusion performed in 1882.

Before donated blood is used for a transfusion, it undergoes rigorous testing to ensure both safety and compatibility. The process includes several key steps:

Health and Quality Screening: Potential donors are evaluated through health questionnaires to assess their suitability. Additionally, the blood is tested to ensure the donor's hemoglobin levels are satisfactory.12
Blood Typing: Blood is classified according to the ABO blood group system and the Rh system to ensure it is compatible with the recipient.32
Pathogen Screening: Blood is screened for infectious agents, including HIV, hepatitis B, hepatitis C, and HTLV-I/II. Testing methods include detecting antibodies, viral antigens, and using polymerase chain reaction (PCR) to identify viral genetic material.14
Compatibility Testing: Before a transfusion, a direct match test is performed by testing the recipient’s serum against the donor’s cells to prevent adverse immune reactions.2

These measures, combined with processes like leukoreduction, significantly minimize the risks associated with transfusion.12