Red Blood Cell (RBC) Antigen Typing: A1

CPT: 86905
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Test Details


Group A subgroup typing of a potential organ donor for A1 may be important, as it may preclude a solid organ transplant to a group O or group B recipient. ABO antigens are expressed on the vascular endothelium of organs. Major incompatibility between donor ABO antigens and recipient plasma can result in acute humoral rejection of the transplanted organ. The occurrence of the A1 antigen is 34% in Caucasians, 19% in Blacks, and 27% in Asians. A1 is present in 80% of group A individuals.


Presence of potent cold agglutinins, a positive direct antiglobulin test, and (in some cases) bacteremia may interfere with test interpretation.



Specimen Requirements


Whole blood


1 mL

Minimum Volume

0.5 mL


Lavender-top (EDTA) tube

Storage Instructions

Specimens should be tested as soon as possible or within 72 hours of collection. Samples that cannot be tested immediately should be stored at 2°C to 8°C. Do not freeze red cells.

Stability Requirements



Room temperature

72 hours


72 hours

Causes for Rejection

Gross hemolysis; bacterial or other contamination

Clinical Information

Special Instructions

For ABO Group, refer to test 006056. For ABO Group and Rh Typing, refer to test 006049.


Fung MK, Grossman JB, Hillyer CD, Westoff CM, eds. AABB Technical Manual. 18th ed. Bethesda, Md: American Association of Blood Banks;2014.
Reid ME, Lomas-Frances CG, Olsson ML, eds. Blood Group Antigen Facts Book. 3rd ed. London, England: Academic Press; 2012.


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
006002 A1 RBC Antigen Typing 844-1 006001 A1 RBC Antigen Typing 844-1

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