For over 40 years, rodent hepatocytes have been an integral component for research into basic aspects of liver physiology, toxicology, and metabolism of xenobiotic compounds. These studies were extended to human hepatocytes for performance of pre-clinical drug toxicity and metabolism assays. Metabolism assays using human cells are essential to assess the potential for drug-drug interactions between new and existing therapeutic compounds. These cells have also been used for cell transplantation, offering an alternative approach to treat patients with acute liver failure or with metabolic disease.
The products usually used to isolate human hepatocytes are ill defined, lyophilized collagenase enzymes that are tan to dark brown in color. These crude or enriched collagenase products are prepared from minimally purified Clostridium histolyticum culture supernatants. These products contain collagenases and neutral proteases that are essential for tissue dissociation. In addition, these crude mixtures contain other contaminants such as endotoxin, other enzymes, and pigment. The lot to lot variability commonly observed when using these products directly reflects the biological variability of enzymes secreted in the bacterial culture supernatants.
In contrast, VitaCyte’s CIzyme™ HH product is prepared from purified bacterial collagenases and protease, minimizing contamination of the final product with other enzymes, pigment, and endotoxin.
The adoption of CIzyme™ HH for your human hepatocyte isolation procedure eliminates the need for lot qualification and provides improved control of the cell isolation process since rigorous characterization of these enzymes by VitaCyte ensures the manufacture of a consistent purified enzyme product. A more thorough discussion of the benefits of using purified enzymes for hepatocyte isolations are discussed here.
Description of CIzyme™ HH product
The enzyme formulation used in CIzyme™ HH was developed in collaboration with Dr. Stephen Strom’s lab at the University of Pittsburgh. This formulation has been used in > 100 human hepatocyte isolation procedures. Like other application specific products, CIzyme™ HH contains an optimal concentration of highly purified and rigorously characterized collagenase and neutral protease to provide consistent and reliable digestion of human liver tissue for the isolation of hepatocytes. The cell isolation protocol used in these experiments is a modified Seglen procedure and is described in the above report.
|Pack Size 1.25 M CDA Units & 1.1 M NP Units|