Final answer:
Component addition order in RPR testing maintains reliable results for blood typing. Agglutination with anti-B serum indicates blood type B or AB. A cross-match assay is done to ensure transfusion compatibility.
Step-by-step explanation:
Maintaining an order of component addition in the card testing area for RPR testing is critical for ensuring accurate and reliable results. This procedure is essential for the typing of both recipient's and donor's blood before a transfusion using a bedside card. The card has three wells with different antibodies to facilitate the identification of specific blood antigens.
Agglutination occurs when the antigens in the patient's red blood cells react with the corresponding antibodies on the test card. For example, if a patient's blood agglutinates with anti-B serum, it indicates the presence of B antigens in the blood, which means the patient has blood type B if there is no agglutination with anti-A serum or A if there is agglutination with both serums. Separately, a cross-match assay is performed to confirm compatibility between donor and recipient blood before a transfusion to prevent transfusion reactions.