REFLECT AND APPLY Referring to Question $23,$ how would you purify protein $\mathrm{X}$ using ion-exchange chromatography if it turns out the protein is only stable at a pH between 6 and $6.5?$

Step by Step Solution: Step 1. Prepare an ion-exchange column with resin that has a positive or negative charge opposite to the protein X. Step 2. Load the protein mixture onto the column. Step 3. Wash the column with buffer at pH higher than 6.5 to remove any unbound proteins. Step 4. Elute protein X out of the column using a gradient buffer with decreasing pH values between 6 and 6.5. The protein should bind to the resin at pH>6.5 and be released at pH