Tagged protein purification products

Tagged protein purification selection guide

To find the media or prepacked columns that suit your needs, choose the option below that best describes your application.

What affinity tag are you using?

We offer a variety of products containing IMAC media precharged with nickel or cobalt ions. These products include prepacked columns for use with chromatography systems, prepacked formats for manual purification, and loose media (resins). Options containing uncharged IMAC media are also available. We recommend products containing the following media types based on your purification priorities:

  • High purity: TALON Superflow, which is precharged with cobalt ions
  • Avoiding nickel leakage: Ni Sepharose excel, which is precharged with nickel ions
  • High binding capacity: Ni Sepharose High Performance, which is precharged with nickel ions
  • Ability to scale up purification: Ni Sepharose 6 Fast Flow, which is precharged with nickel ions
  • Flexibility in metal ions used: Uncharged IMAC media

The choice of metal ion affects binding specificity and strength. The requirements for this purification step will help with this choice. Nickel (Ni2+) is the most popular metal ion for histidine-tagged (his-tagged) protein purification. But nickel tends to bind nonspecifically to host proteins containing histidine clusters. Cobalt (Co2+) interacts more specifically with his-tags, often giving a more pure protein. GE offers many products containing media precharged with nickel or cobalt ions. Uncharged IMAC media are flexible options for preparing media charged with metal ions other than nickel or cobalt, such as zinc or copper.

Mammalian (e.g., CHO cells) and insect cell culture media contain substances that could reduce the yield of purified histidine-tagged (his-tagged) proteins. These components lower the binding to the IMAC medium by stripping the chelated metal ion. To improve protein yield, the sample can be pretreated to remove the interfering substances. Another option is to use a medium (e.g., Ni Sepharose excel) that binds to his-tagged proteins in the presence of metal stripping agents.

Before applying a crude sample to an IMAC column, the sample is typically clarified using centrifugation and filtration. An alternative is to apply an unclarified, crude sample to an appropriate column directly after thorough cell disruption. This option can save time and help to minimize protein degradation. GE provides a wide range of products that have been designed to purify histidine-tagged proteins from unclarified samples.

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