ABO PRACTICAL ESSENTIAL CONCEPTS
REVIEW
◉ What is the purpose of Rh typing?
Answer: To determine whether the patient's RBCs possess the D
antigen.
◉ What must be negative for the Rh result to be trusted?
Answer: The Rh control must be negative.
◉ What does a positive Rh control indicate?
Answer: It indicates nonspecific agglutination and that the Rh result
is invalid.
◉ What is the critical rule for Rh typing?
Answer: Rh control must be negative to trust the Rh result.
◉ What is the purpose of the Antibody Screen?
Answer: To detect unexpected clinically significant antibodies in
patient plasma/serum.
◉ Why are Group O cells used in the Antibody Screen?
, Answer: Because Group O cells do not have A or B antigens that
would interfere with the test.
◉ What is the sequence of steps in the Antibody Screen procedure?
Answer: LABEL → PLASMA → CELLS → IS → ENHANCE → 37°C →
WASH → AHG → CHECK CELLS.
◉ What does the Autocontrol determine?
Answer: Whether the patient's plasma reacts with their own RBCs.
◉ What is the purpose of the Immediate-spin crossmatch?
Answer: To primarily detect ABO incompatibility.
◉ What does the AHG crossmatch detect?
Answer: Clinically significant IgG incompatibility.
◉ What is the critical concept in Forward ABO typing?
Answer: Agglutination = antigen is present.
◉ What is the critical concept in Reverse ABO typing?
Answer: Reverse typing tells you which antibodies are in the plasma.
REVIEW
◉ What is the purpose of Rh typing?
Answer: To determine whether the patient's RBCs possess the D
antigen.
◉ What must be negative for the Rh result to be trusted?
Answer: The Rh control must be negative.
◉ What does a positive Rh control indicate?
Answer: It indicates nonspecific agglutination and that the Rh result
is invalid.
◉ What is the critical rule for Rh typing?
Answer: Rh control must be negative to trust the Rh result.
◉ What is the purpose of the Antibody Screen?
Answer: To detect unexpected clinically significant antibodies in
patient plasma/serum.
◉ Why are Group O cells used in the Antibody Screen?
, Answer: Because Group O cells do not have A or B antigens that
would interfere with the test.
◉ What is the sequence of steps in the Antibody Screen procedure?
Answer: LABEL → PLASMA → CELLS → IS → ENHANCE → 37°C →
WASH → AHG → CHECK CELLS.
◉ What does the Autocontrol determine?
Answer: Whether the patient's plasma reacts with their own RBCs.
◉ What is the purpose of the Immediate-spin crossmatch?
Answer: To primarily detect ABO incompatibility.
◉ What does the AHG crossmatch detect?
Answer: Clinically significant IgG incompatibility.
◉ What is the critical concept in Forward ABO typing?
Answer: Agglutination = antigen is present.
◉ What is the critical concept in Reverse ABO typing?
Answer: Reverse typing tells you which antibodies are in the plasma.
