Animal subcellular fractions, such as microsomes, S9, and cytosol, are used in preclinical drug development as in vitro test systems in assays predictive of in vivo behaviors and conditions. These assays specifically provide information on hepatic and extrahepatic metabolism of a drug compound as part of its ADME (absorption, distribution, metabolism, and excretion) profile or for species comparison to inform later definitive in vitro or in vivo ADME and drug-drug interaction studies.
Rat Subcellular Fractions for In Vitro Assays in Preclinical Drug Development
We offer pooled microsomes, cytosol, and S9 fractions isolated from liver, intestine, kidney, and lung tissue from four different strains of rat (Fischer 344, International Genetic Standard (IGS) Sprague-Dawley, Wistar and Wistar Han). Other custom preparations of rat tissue may be available upon request.
We offer pooled hepatic subcellular fractions isolated from liver tissue of four different strains of rat (Fischer 344, Sprague-Dawley, Wistar, and Wistar Han), demonstrating high enzyme activity levels. Options include tritosomes (lysosomes treated with surfactant for catabolism or lysosomal stability assays) and matching microsomal, S9, and cytosolic fractions from male or female donor pools to minimize variation. We also offer rat liver microsomes treated with prototypical inducers for use as a positive control in ex vivo enzyme induction or other drug metabolism studies.
Make sure your microsomes and S9 fractions are properly activated
For best results from assays using microsomes and S9 fractions, we recommend using NADPH regeneration to support high metabolism levels by ensuring that the NADPH levels are not a limiting factor in your incubations. Our preferred system, RapidStartTM , uses an enzymatic reaction that converts NADP to NADPH, which is then used as a cofactor by CYPs and oxidized back to NADP, and the cycle continues ensuring stable NADPH levels throughout the incubation. RapidStartTM NADPH regeneration is easily activated by simply adding water. Our easy-to-use formula is the most convenient and flexible NADPH regenerating system you’ll find, allowing users to easily tailor the system’s capability by simply varying the amount of water added. RapidStartTM is perfect for long- and short-term incubations and supports the function of recombinant enzymes and subcellular fractions, allowing you to achieve the most accurate and reliable data during your in vitro assays.
For studies using rat tritosomes, our specially formulated 10x catabolism buffer is optimized to enable premium catabolic performance in in vitro assays. All of the catabolic data presented in our published scientific posters rely on this specially formulated buffer, optimized to facilitate maximum catabolic activity in lysosome/tritosome assays. Read more in our Tritosome Technical Tips guide.
Don’t see what you need? Other preparations can be made available!
If you require cell fractions not available through our standard product offerings, Custom Subcellular Preparations can be easily ordered to meet the specific needs of your study.
Our designated Custom Products team regularly prepares and isolates cells and/or subcellular fractions from more than 45 different species and has capabilities to meet unique needs that are unavailable through most vendors– non-standard rodent strains, farm animals, insects, precarious tissue isolations such as adrenal gland or jejunum. Our specialists can carry out over 40 characterization assays, providing the end-user with a good foundation for their DMPK assays. See our Custom Products page for examples of past custom preparations or get in touch with a specialist to find out how we can meet your needs.