Cross Match & PhenotypedAntigen Negative Packed Red Cells with Screening

Specimen Required

Fasting Required

Purpose of the Test

This test is typically performed prior to a blood transfusion to ensure compatibility between the donor’s and the recipient’s blood. Crossmatching is done to check for any possible reactions between the recipient’s antibodies and the donor’s red blood cells. Phenotyping and antigen testing are done to determine the blood type of the donor’s red blood cells and to match them with the recipient’s blood type.

When this test is required

This test is typically requested before a blood transfusion, especially if the patient has had a prior transfusion or is at risk of needing a transfusion.

What the Test Detects

The crossmatch and phenotyping/antigen testing are blood tests that are performed to ensure compatibility between the donor’s and the recipient’s blood prior to a blood transfusion. Crossmatching checks for possible reactions between the recipient’s antibodies and the donor’s red blood cells, while phenotyping and antigen testing determine the blood type of the donor’s red blood cells and match them with the recipient’s blood type.

Preparation for the Test

There is typically no specific test preparation needed for this test.

Sample Requirements

A blood sample is required from both the donor and the recipient.

Additional Notes

Crossmatching and phenotyping/antigen testing are important steps to ensure a safe blood transfusion. The results of these tests can take several hours to obtain, so it is important to plan accordingly when scheduling a transfusion. Additionally, the test may need to be repeated if a transfusion is delayed, as blood type and antibody levels can change over time.

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