Endotoxin testing is an important standard of many proteins’ quality control reporting. Verifying the amount of endotoxin in a sample of protein is critical to ensure that it is safe for research and therapeutic applications.
Eluting your protein of interest is the final step in affinity chromatography before obtaining a pure, useful sample for further study. Common methods include elution using proteolytic elution, low pH elution, and denaturant elution. An alternative to these options is what’s known as Gentle Elution Buffer, or 3.6 M MgCl2 pH 6.6.
Based on the natural affinity between biotin and streptavidin, Strep-tag is one of the most specific-binding speciality tags on the market. Its high specificity positions it as an alternative or supplement to His-trap, which is based on a non-specific binding of His to metal ions in resin.
Human growth hormone (hGH), also known as somatropin, is a hormone secreted by the pituitary gland. This blog post gives an overview of the uses and features of hGH, as well as its optimized soluble purification using the CL7/Im7 system.
His-tag and FLAG are two of the most commonly used tags in affinity purification. While both systems have positive features, disadvantages such as multiple chromatography steps, low resin binding capacity, and non-specific binding can result in lower purity and yield than desired.
Improvements on the methods and manner of delivery of ribonucleoprotein (RNP) complexes have been made in order to improve efficiency and minimize off-target effects. This blog post reviews the current state of RNP complex delivery systems.
Low protein yield is a common issue in protein purification, especially when it comes to isolating large or complex structures. In lieu of using denaturants to elute protein from an affinity column, protease elution can be a welcome alternative to give tag-free protein.
The OD 260/280 ratio is a valuable tool in protein purification; it serves as a guidepost for the purity and composition of a sample. This blog post will talk about the importance of measuring this value throughout the process of purifying proteins.
In 2013, crystallographer and UAB Professor Dmitry Vassylyev was purifying proteins for crystallography studies when he began to develop the CL7/Im7 system. At the time, no single affinity chromatography system existed that could give him the desired ultra-high purity, tag-free protein with reasonable yield in a short amount of time.
Biosimilars are functionally significant proteins with therapeutic potential. This blog post highlights the purification of several biosimilar proteins using the CL7/Im7 system.
Membrane proteins are difficult to purify due largely to their hydrophobic regions. When the proteins are in solution, these exposed regions can form strong non-specific interactions with each other, cytoplasmic proteins, or nucleic acids.
Multi-subunit proteins present roadblocks because of their size and the expression of multiple units. In this blog post, we discuss the one-step purification of ttRNAP and mtRNAP, two bacterial RNA polymerases, using the CL7/Im7 system.
