TriAltus Bioscience Launches Im7 Affinity Chromatography Resin with Increased Binding Capacity

Modification doubles binding capacity for CL7/Im7 single-step protein purification system

BIRMINGHAM, Ala.  TriAltus Bioscience, LLC today announced the launch of its Activated Im7 affinity chromatography resin for the CL7/Im7 protein purification system. This new version more than doubles the single-step protein purification system’s original binding capacity from 15 – 20 mg/ml to 35 – 40 mg/ml of CL7-tagged protein.

Proprietary chemical modifications to the Activated Im7 Resin enable it to bind more Im7 protein, and therefore, more CL7-tagged protein. In addition to being sold in bulk, the new Im7 resin will be packed into TriAltus gravity flow columns and FPLC columns.

“Combined with our previously established affinity and salt loading advantages, the CL7/Im7 system demonstrates clear superiority over His-tag and other commercial affinity tag systems,” explained TriAltus Co-founder and CEO Robert Shufflebarger. “The result is the most efficient and universal tool available for simple, cost-effective, ultra-high-affinity purification of complex proteins, which is essential for advanced structural and industrial applications as well as gene therapy research.”

Proteins are widely used in life science and pharmaceutical research, with more than 80 percent of drugs in development made of proteins or acting upon proteins, yet protein production remains cumbersome and inefficient, lagging behind advances in protein analysis. Protein sample isolation often requires 4 to 5 purification steps, with most of the target protein lost in the process.

TriAltus leverages the remarkably strong binding affinity between bacterial toxins called colicins and their specific immunity proteins. The company’s CL7 tag system is based specifically on ultra-high-affinity interaction between CL7 – the inactive variant of Colicin E7 DNAse – and its inhibitor, immunity protein 7 (Im7). The Im7 inhibitor is covalently crosslinked to agarose beads, while the CL7 domain is tagged to the target protein.

The CL7 tag can be inserted into genes of both eukaryotic and prokaryotic proteins, which can then be moved to an expression vector or expressed from native cells without over-expression. An engineered protease site releases the target protein from the bound CL7 tag, enabling one-step, high-yield, high-purity and high-activity (HHH) purification with 97 to 100 percent purity. Once the protease has cleaved off the protein, the CL7 tag can be removed from the column and the Im7 resin reused.

Unlike most published purification processes for challenging proteins – which involve multistep, multiday protocols, with higher costs and lower yields – the CL7/Im7 single-step system enables HHH purification, the foundation for most modern biological studies such as proteomics, interactomics and in vitro drug screening.

Simple, reusable and resilient, TriAltus’ Activated Im7 Resin has been used to purify a variety of proteins – including membrane and multisubunit proteins. The Im7 resin is capable of up to 100 reactivations, retaining a 1:1 molar binding ratio.

The CL7 technology was invented by a team lead by Dmitry Vassylyev, Ph.D., TriAltus co-founder and professor of biochemistry and molecular biology at the University of Alabama Birmingham (UAB). The foundational study was published in 2017 in the Proceedings of the National Academy of Sciences. TriAltus Bioscience holds the exclusive, worldwide license to the CL7 protein purification technology platform, which was licensed from UAB in 2018.

For more information, visit our website, connect with us on LinkedIn, Facebook and Twitter, or email us at or call 205-453-8242. TriAltus offers a limited free sample program for researchers to validate the CL7/Im7 system in their own labs.


About TriAltus Bioscience
TriAltus Bioscience, LLC ( provides life scientists with tools for production and purification of genetically engineered proteins. Our novel affinity tag system delivers proteins with ultra-high purity and yield in a single step. For more information, visit our website, connect with us on LinkedIn, Facebook and Twitter, or email us at or call 205-453-8242. For commercial use or resale, contact us at

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Nancy Wenger
TriAltus Bioscience
205-453-8242 x103