You are conducting an antibody identification and suspect your patient has developed anti-Fya based on your initial rule-ins and rule-outs. You've completed a 3-cell screen and 10-cell antibody panel using the test tube method but despite this comprehensive testing, anti-E has not yet been ruled out. The next cell you select should meet the following criteria:
- Negative for Fya (so it will not react with the anti-Fya that has been identified in the serum of the patient).
- Homozygous for big E (big E-positive and little e-negative, so that it will react most strongly with anti-E if present).
You proceed to select a 6-cell panel with diverse antigen expressions. Within this panel, four cells (3–6) meet the first criterion (Fya negative). Of these cells, three (4–6) are big E-positive, and of these, only one cell (4) is homozygous for E (big E positive and little e negative). Therefore, cell 4 would be a suitable rule-out cell in this case.
| Rh-Hr | Kell | Duffy | Kidd | Lewis | MNSs | P | Lutheran | Xg |
Donor Cell Number | D | C | c | E | e | Cw | K | k | Kpa | Jsa | Fya | Fyb | Jka | Jkb | Lea | Leb | M | N | S | s | P1 | Lua | Lub | Xga |
1 | 0 | + | + | 0 | + | 0 | 0 | + | 0 | 0 | + | + | + | + | 0 | + | + | 0 | 0 | + | + | 0 | + | 0 |
2 | + | + | 0 | 0 | + | + | 0 | + | 0 | 0 | + | 0 | + | + | + | 0 | 0 | + | 0 | + | + | 0 | + | + |
3 | + | + | 0 | 0 | + | 0 | + | + | 0 | 0 | 0 | + | 0 | + | 0 | + | + | + | 0 | + | + | 0 | + | + |
4 | + | 0 | + | + | 0 | 0 | 0 | + | 0 | 0 | 0 | 0 | + | 0 | 0 | 0 | + | 0 | 0 | + | + | 0 | + | + |
5 | 0 | 0 | + | + | + | 0 | 0 | + | 0 | 0 | 0 | + | 0 | + | 0 | + | + | + | + | + | + | 0 | + | 0 |
6 | 0 | 0 | + | + | + | 0 | 0 | + | 0 | + | 0 | 0 | + | 0 | + | 0 | + | + | 0 | + | + | 0 | + | 0 |