Red blood cells which are to be tested with AHG are washed to

Red blood cells which are to be tested with AHG are washed to

• A. Remove unbound serum globulins
• B. Remove bound antibodies
• C. Remove plasma proteins
• D. Remove RBC debris

Answer: (A)

In antiglobulin testing, the goal is to detect antibodies that are already attached to red cells (or antibodies that will cause agglutination in the test phase) without interference from other soluble components. Washing the red cells thoroughly with saline removes unbound serum immunoglobulins and other serum proteins. If unbound antibodies remain, the antihuman globulin reagent could bind to them in solution or cause non-specific bridging, leading to background or false-positive reactions. By removing these unbound serum globulins, any agglutination observed with AHG is more specifically due to antibodies (or complement) bound to the red cells. Removing bound antibodies would defeat the test’s purpose, and removing plasma proteins or RBC debris isn’t the primary reason for this washing step.

In antiglobulin testing, the goal is to detect antibodies that are already attached to red cells (or antibodies that will cause agglutination in the test phase) without interference from other soluble components. Washing the red cells thoroughly with saline removes unbound serum immunoglobulins and other serum proteins. If unbound antibodies remain, the antihuman globulin reagent could bind to them in solution or cause non-specific bridging, leading to background or false-positive reactions. By removing these unbound serum globulins, any agglutination observed with AHG is more specifically due to antibodies (or complement) bound to the red cells. Removing bound antibodies would defeat the test’s purpose, and removing plasma proteins or RBC debris isn’t the primary reason for this washing step.