Table 1 Coded values of independent variables used to study the effect of pH and salt (NaCl) concentration on protein extraction efficiency
Independent variable | Code levela | ||||
|---|---|---|---|---|---|
-1.414 | -1.0 | 0.0 | 1.0 | 1.414 | |
pH | 7.6 | 8.0 | 9.0 | 10.0 | 10.4 |
Salt concentration (M) | 0.034 | 0.2 | 0.6 | 1.0 | 1.2 |