How Blood Is Tested and Stored
Testing and storage are at the heart of blood safety. Understanding these steps reassures donors and recipients that the system is carefully controlled.
If infections or mismatched blood are given to a patient, the consequences can be serious. Testing aims to:
· Protect patients from dangerous infections.
· Ensure the right blood type goes to the right person.
· Identify rare blood types or special antibodies.
1. Blood grouping and typing
o ABO group – A, B, AB, or O.
o Rh factor – positive (+) or negative (−).
2. These basic groups are essential to avoid severe immediate reactions.
3. Antibody screening
o Some patients have antibodies against specific red cell antigens (beyond ABO and Rh).
o Screening helps identify these and choose donor units that will not be attacked by the patient’s immune system.
4. Infectious disease screening
Most systems test every unit for:
o HIV.
o Hepatitis B (HBsAg and sometimes other markers).
o Hepatitis C.
o Syphilis.
o Often malaria or other region‑specific infections.
5. Tests are chosen to detect infections even when the person feels healthy and has no symptoms.
What happens if a test is positive?
If a donation tests positive for a serious infection:
· The blood unit is discarded and will not be used for transfusion.
· Usually, the donor is notified confidentially, given counselling, and advised to see a doctor or clinic for further care and confirmatory testing.
· Depending on the infection and national rules, the donor may be permanently deferred from future donation.
This process protects patients and gives donors important health information they may not have known.
Each blood component has its own storage needs.
1. Red blood cells
o Stored at 2–6°C in special blood refrigerators.
o Have a limited shelf‑life (often around 35–42 days, depending on the preservative used).
o Monitored continuously for temperature stability.
2. Platelets
o Stored at room temperature (around 20–24°C) with constant gentle agitation to keep them functional.
o Shelf‑life is short, often 5–7 days, so steady donations are needed.
3. Plasma
o Frozen at −18°C or lower (often −25°C or below) as fresh frozen plasma.
o Can be stored for months, depending on regulations.
o Thawed when needed for patients with clotting problems.
4. Cryoprecipitate and special products
o Made from plasma and stored frozen.
o Used for specific clotting factor deficiencies.
All storage equipment is checked daily. Any temperature excursions or equipment failures trigger alarms and may lead to units being discarded to maintain safety standards.