Automated Versus Manual Protein Purification

Bio-Rad Laboratories, Inc., a multinational manufacturer and distributor of life science research and clinical diagnostic products, today announced the availability of a technical note (bulletin 5513A), which compares the performance and reproducibility of the automated Profinia™ protein purification system to traditional manual gravity-flow column purification for GST, (glutathione-S-transferase) affinity purification and desalting.

To enable a valid comparison, the B-PER GST fusion protein purification kit from Pierce Biotechnology was chosen, and identical application and elution volumes were used for the columns tested between the two systems.

During the test, unlike the manual gravity-flow purification kit, the Profinia system did not require user handling between the application of the sample and the conclusion of the affinity purification and desalting steps.

Those who conducted the test concluded that reduced sample handling and hands-on time were the principal benefits over manual purification. The Profinia system was superior in protein yield and reproducibility and was equivalent to the manual system in terms of protein purity.

One key feature of the Profinia system is the automated collection of purification data, an option that is not available with the manual system. The automated collection of purification data simplifies the evaluation of the effectiveness of purification and diagnostic purpose for trouble shooting. These data are captured in a report that contains chromatograms, continuous records of various method parameters, yield, volumes, and purification conditions.

Another key feature discussed in the bulletin is the integration of the desalting step into the purification step. The immediate automated desalting after affinity purification not only saves time but also provides ready-to-use protein for downstream assays.