You are given an anion exchange column (basic column: see Ion Exchange Chromatrography in lecture materials), low salt buffer (100 mM NaCI), and high salt buffer (1 M NaCI) both at pH 7.0 If you loaded the above mixture of proteins on the column in low salt buffer, specify the order of the strengths in which the proteins would be retained by the column. What do you expect to happen when the high salt buffer is applied to the column with the bound protein(s)? Why? If a linear 100mM- 1 M NaCI gradient of salt is applied to the column, which protein(s) do you expect to be eluted first? Why? You load the above protein mixture to an SDS-PAGE, run the gel and then stain it with silver. Sketch the observed results and clearly label all proteins. How would your sketch change if rather than silver stain, you performed a Western Blot followed by immunostaining with an antibody specific for Protein X?
