Purification of lactoferrin by expanded-bed column chromatography

Lactoferrin, which binds iron very tightly but reversibly and is a useful p rotein because of its various biological functions, was purified from defat ted milk by use of an expanded-bed column with Streamline SP as adsorbent. Adsorption of lactoferrin in defatted milk is found to obey a Langmuir isot herm. The isotherm is also obeyed in phosphate buffer, and the amount of la ctoferrin adsorbed decreased rapidly with an increase of NaCl in the buffer . With the expanded-bed column nearly 90% of lactoferrin in the applied mil k is recovered with purity of ca. 90% through high apparent velocity of ca. 150 cm/h in the bed.