Purification protocols for immunoglobulins generally include affinity binding to Protein A or G chromatography media, washing unbound proteins, and eluting with a low pH buffer. The resulting purified antibodies are often too dilute for downstream studies or long-term storage. Dialysis is often necessary to concentrate the antibody and/or exchange the buffer into one that preserves protein activity. Ultrafiltration achieves the same result faster, with up to 99% immunoglobulin recovery and one-step salt removal (see Concentration, Desalting, and Buffer Exchange protocol).
Purification and concentration of Rabbit IgG with Prosep® A and Prosep® G Montage® Antibody Purification Kits and Amicon® Ultra-15 mL centrifugal filters.
Figure 1.Concentration of rabbit IgG with Amicon Ultra-15 devices. The IgGs were purified using Montage PRSEP-A pr PROSEP-G Antibody Purification Kits. The lines show IgG volume reduction, while the bars show a proportional increase in IgG concentration after 20 min of centrifugation time.
Figure 2.SD-PAGE gel of purified rabbit IgG before and after concentration with Amicon Ultra-15 devices.