Rh antigen testing must be done with strict adherence to manufacturer's instructions and a clear understanding of the limitations of the reagents used in the procedure. The table below delineates some of the more commonly seen false-positive reactions with Rh typing reagents and provides insight into the causes and corrective actions that may be undertaken when these problems are presented.
Likely Cause | Corrective Action |
Cell suspension too heavy | Adjust suspension; retest |
Rouleaux | Use saline-washed cells; retest |
Bacterial contamination of reagent vial | Open new vial of reagent; retest |
Incorrect reagent selected | Read vial label carefully when repeating test |
Centrifugation too long | Repeat test using shorter centrifugation time, per package insert/SOP |