The table below delineates some of the more commonly seen false-negative 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 |
| Failure to follow manufacturer's instructions precisely | Review direction circular; repeat test |
| Resuspension too vigorous | Resuspend all tubes gently during repeat testing |
| Immunoglobulin-coated cells (in vivo) | Use saline-active typing reagent; repeat test |
| Incorrect reagent selected | Read vial carefully; repeat test |
| Reagent deterioration | Open new vial, perform appropriate QC; repeat test |
