Table 1.
Thirty-two different cleaning protocols including one control (wash with PBS) were evaluated for cleaning efficiency of fouled MabSelect SuRe resin
| CIP protocol | CIP step 1 | CIP step 2 | CIP step 3 | CIP step 4 |
| 1 | PBS, pH 7.4 (Control) | |||
| 2 | 0.1 M citric acid pH 3.0 | |||
| 3 | 0.1 M citric acid pH 2.5 | |||
| 4 | 6 M Gua-HCl | |||
| 5 | 100 mM 1-thioglycerol, pH 8.5 | |||
| 6 | 0.1 M citric acid pH 3.0 | 6 M Gua-HCl | ||
| 7 | 0.1 M citric acid pH 3.0 | 100 mM 1-thioglycerol, pH 8.5 | 6 M Gua-HCl | |
| 8 | 0.1 M citric acid pH 3.0 | 100 mM 1-thioglycerol, pH 8.5 | 6 M Gua-HCl | 0.1 M citric acid pH 3.0 |
| 9 | 8 M urea, 0.1 M citric acid, pH 3.0 | |||
| 10 | 8 M urea, 1 M NaCl, 0.1 M citric acid, pH 3.0 | |||
| 11 | 100 mM NaOH | |||
| 12 | 0.1 M citric acid pH 3.0 | 100 mM NaOH | ||
| 13 | 0.1 M citric acid pH 2.5 | 100 mM NaOH | ||
| 14 | 100 mM NaOH | 0.1 M citric acid pH 3.0 | ||
| 15 | 0.1 M citric acid pH 3.0 | 100 mM NaOH | 0.1 M citric acid pH 3.0 | |
| 16 | 8 M urea, 0.1 M citric acid, pH 3.0 | 100 mM NaOH | ||
| 17 | 8 M urea, 1 M NaCl, 0.1 M citric acid, pH 3.0 | 100 mM NaOH | ||
| 18 | 0.1 M ascorbic acid | 100 mM NaOH | ||
| 19 | 0.1 M citric acid pH 3.0 | 70% ethanol | 100 mM NaOH | |
| 20 | 0.1 M citric acid pH 3.0 | 30% isopropanol | 100 mM NaOH | |
| 21 | 0.5 M NaOH | |||
| 22 | 0.1 M citric acid pH 3.0 | 0.5 M NaOH | ||
| 23 | 0.1 M citric acid pH 3.0 | 0.3 M NaOH | ||
| 24 | 100 mM 1-thioglycerol, pH 8.5* | 100 mM NaOH | ||
| 25 | 100 mM 1-thioglycerol, pH 8.5 | 100 mM NaOH | ||
| 26 | 50 mM 1-thioglycerol, pH 8.5 | 100 mM NaOH | ||
| 27 | 100 mM DTT, pH 8.5 | 100 mM NaOH | ||
| 28 | 0.1 M citric acid pH 3.0 | 100 mM 1-thioglycerol, pH 8.5 | 100 mM NaOH | |
| 29 | 0.1 M citric acid pH 3.0 | 100 mM 1-thioglycerol, pH 8.5 | 100 mM NaOH | 0.1 M citric acid pH 3.0 |
| 30 | 100 mM 1-thioglycerol, pH 8.5 | 0.5 M NaOH | ||
| 31 | 0.1 M citric acid pH 3.0 | 100 mM 1-thioglycerol, pH 8.5 | 0.5 M NaOH | |
| 32 | 100 mM NaOH | 100 mM 1-thioglycerol, pH 8.5 |
The 32 CIP protocols contained sequences with 1–4 cleaning steps. The composition of the reducing agent containing solutions were: 50 or 100 mM 1-thioglycerol, 25 mM Tris, 0.15 M NaCl, 25 mM KCl, 1 M EDTA (*without EDTA), pH 8.5 or 100 mM DTT, 25 mM Tris, 0.15 M NaCl, 25 mM KCl. For the CIP steps where no chemical is indicated, ultrapure water was added to the wells in the 96-well filter plate. The remaining protein impurities on the fouled MabSelect SuRe resin after cleaning using these CIP protocols is presented in Figure 8. Note: US patent 6972327 (Immunex Corporation) apply to CIP protocols 7 and 8.