Rh antigen testing must strictly adhere to the manufacturer's instructions and clearly understand the limitations of the reagents used in the procedure. Table 6 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.
Table 6. False-Positive Reactions with Rh Typing Reagents.| 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 |
