Testing For Blood Types

Question 1

What do your u need to test to provide compatible blood for transfusion?

Answer 1

• ABO and RhD blood groups on patient’s RBCs.

- An antibody screen on the patient’s plasma- known as ‘group and screen’

Question 2

An antibody screen is performed to exclude any clinically significant immune antibodies. How?

Answer 2

1) Patient’s plasma is incubated with 2 or 3 different fully typed ‘screening’ red cells- which are known to possess all blood groups that matter clinically.
2) If antibody screen is negative, any donor blood which is ABO and RhD compatible can be given.
3) If the antibody screen is positive, antibodies must be identified with the use of a large panel of RBCs. You’d then use donor blood that lacks that corresponding antigens for cross matching before transfusion.

Question 3

What’s the sequence of compatibility testing?

Answer 3

You take a blood sample from the patient, then:

1) ABO group test (test the sample with known anti-A and anti-B reagents)
2) RhD group test (test patient’s red cells with known anti-D reagents)
3) Select Donor blood of the same ABO and RhD group
4) Antibody screen with or without antibody panel to identify antibodies.
5) Cross-matching: patient’s serum mixed with chosen donor red cells- should not react. If it does (agglutinates) it’s incompatible.

Question 4

Who can donate blood?

Answer 4

Blood’s collected in the UK only from volunteer, unpaid donors between 17-70 years of age.

Donors are excluded if they have any disease that would make donation dangerous for them or dangerous for transfusion to the recipient.