Disclosed is a method for producing a host cell-protein (HCP) reduced anti-IL-13 antibody, or antigen-binding fragment thereof, preparation from a sample mixture comprising an anti-IL-13 antibody, or antigen-binding fragment thereof, and at least one HCP, said method comprising: (a) contacting said sample mixture to Protein A affinity chromatography resin, washing said affinity chromatography resin with a buffer comprising 0.5 M NaCl, 20 mM Na citrate, at pH 6, and a buffer comprising 25 mM Tris, 100 mM NaCl, pH 7.2 and collecting an affinity chromatography sample (b) subjecting said affinity chromatography sample to a reduction in pH thus forming a reduced pH sample, wherein said reduction in pH is from about 3 to about 4 (c) adjusting said reduced pH sample to a pH of about 4.5 to about 6.5 and contacting said adjusted pH sample to an ion exchange resin and collecting an ion exchange sample and (d) contacting said ion exchange sample to a hydrophobic interactive chromatography (HIC) resin and collecting an HIC sample, wherein said HIC sample comprises said HCP-reduced antibody, or antigen binding portion thereof, preparation.
