| Sample | 0 h (Area) | 24 h (Area) | % IL-2 Recovered | 96 h (Area) | % IL-2 Recovered |
| IL-2 in 10 mM sodium citrate, pH 3.0 | 467,603 | 443,671 | 94.9 | 444,295 | 95.0 |
| IL-2 in 0.1 N acetic acid, pH 3.0 | 452,564 | 443,290 | 98.0 | 441,459 | 97.5 |