These are the results of the crossmatch that was being performed in the transfusion service laboratory while the patient was receiving the two units of O Rh-negative RBCs.
| Cells | Gel IAT* |
| Donor I** | 2+ |
| Donor 2** | 2+ |
| Donor 3 | 3+ |
| Donor 4 | 3+ |
| Donor 5 | 2+ |
| Donor 6 | 3+ |
* IAT = indirect antiglobulin test
** O Rh-negative RBC (Donors 3 - 6 are O Rh-positive)