Protein Purification Methods and Systems

A system for purifying a polypeptide, wherein the system comprises:

• (a) an injection valve for injecting a composition containing the polypeptide into the system, wherein the injection valve is connected to a first immobilized metal affinity chromatography (IMAC) matrix and a pump to control flow of the sample through the first IMAC matrix;
• (b) a column valve for controlling flow path of an equilibration buffer, an elution buffer, and an SEC buffer;
• (c) a desalting column configured to receive flowthrough or eluate from the first IMAC matrix;
• (d) a second IMAC matrix configured to receive flowthrough or eluate from the desalting column;
• (e) a size exclusion chromatography (SEC) column configured to receive flowthrough or eluate from the second IMAC matrix;
• and
• (f) a detection device for detecting the polypeptide in the system.

A method for purifying a His-tagged polypeptide, comprising:

• (a) loading a composition comprising the His-tagged polypeptide onto a first immobilized metal affinity chromatography (IMAC) matrix;
• (b) eluting the His-tagged polypeptide from the first IMAC matrix with an elution buffer to form a first eluate comprising the polypeptide;
• (c) conducting a buffer exchange to remove the elution buffer from the first eluate using a desalting column;
• (d) loading the first eluate from step (c) onto a second IMAC matrix, wherein the second IMAC matrix comprises agarose beads and a nitrilotriacetic acid chelation moiety bound to nickel;
• and
• (e) eluting the His-tagged polypeptide from the second IMAC matrix with a second elution buffer to form a second eluate comprising the His-tagged polypeptide.