Wash solution and method for affinity chromatography
The invention provides a washing method for affinity chromatography in which a wash solution comprising arginine, or an arginine derivative, and a nonbuffering salt, preferably at high pH, greater than 8.0, is effective in removing impurities, such as high molecular weight species and host cell proteins, while also increasing product concentration in the eluate and maintaining a high percent yield of recovered product.
1. A method of producing a purified antibody, antibody fragment, or Fc fusion protein using an affinity chromatography (AC) matrix to which the antibody, antibody fragment, or Fc fusion protein is bound, the method comprising:
(a) loading a mixture comprising the antibody, antibody fragment, or Fc fusion protein onto the AC matrix; and
(b) washing the AC matrix with one or more wash solutions comprising arginine and a halogen salt selected from the group consisting of sodium chloride (NaCl), magnesium chloride (MgCl 2 ) and potassium chloride (KCl), wherein the pH of the one or more wash solutions is greater than 8.0, prior to elution of the antibody, antibody fragment, or Fc fusion protein from the AC matrix.
2. The method of claim 1 , wherein the arginine is at a concentration of or about 0.25 M.
3. The method of claim 1 , wherein the arginine is arginine-HCl.
4. The method of claim 1 , wherein the halogen salt is at concentration of or about 1 M.
5. The method of claim 4 , wherein the halogen salt is sodium chloride (NaCl).
6. The method of claim 1 , wherein the pH of the wash solution is in a range of about 8.5-9.5.
7. The method of claim 6 , wherein the pH of the wash solution is 9.0.