We offer pooled hepatic subcellular fractions isolated from liver tissue of four different strains of rat (Fischer 344, International Genetic Standard Sprague-Dawley (IGS SD), 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.
Rat Liver Microsomes, S9 & Cytosol
Rat microsomes are supplied in 0.5 mL volume at 20 mg/mL protein concentration, suspended in 250 mM sucrose buffer. S9 (1 mL at 20 mg/mL protein concentration) and cytosol (1 mL at 10 mg/mL protein concentration) fractions are packaged in a suspension buffer containing 50 mM TRIS-HCI, (pH 7.4 at 4ºC), 150 mM KCI, and 2 mM EDTA.
Available Pooled Hepatic Subcellular Fractions
Available Rat Liver Microsomes
Available Rat Liver S9
Available Rat Liver Cytosol
Available Rat Liver Tritosomes
Available Treated Liver Microsomes from Male Sprague-Dawley Rat
Utilizing Rat Liver Subcellular Fractions in Preclinical Research
Pooled rat liver cell fractions are used most often in drug metabolism studies for preclinical research defining a drug candidate’s ADME (absorption, distribution, metabolism, and excretion) profile. Our unique preparation methods allow for large donor pools for higher accuracy in average activity levels; large lots for consistency between assays; and availability of matching S9, microsomes, and cytosol for correlation between studies using different test systems.
Microsomes contain the highest concentration of many important drug-metabolizing enzymes including cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes. Homogenate and S9 fractions contain a mixture of membranes and soluble enzymes that can be further fractionated into the cytosol and microsomes subcellular fractions. Homogenate and S9 express a wide variety of phase I and phase II enzymes and are recommended for many different drug metabolism and pharmacokinetics studies. Microsomal fractions are enriched for phase I enzymes, while cytosolic fractions contain various soluble drug-metabolizing enzymes and are a recommended test system for evaluating phase II metabolic reactions of a test compound – especially once reactions have been observed in S9 fractions.
Treated rat lysosomes (Tritosomes): a predictive in vitro test system for catabolism or lysosomal stability studies
Rat liver tritosomes are hepatic lysosomes that have been loaded with Tyloxapol (Triton WR 1339), a non-ionic surfactant. Tyloxapol-containing lysosomes exhibit decreased density and can be more efficiently isolated away from mitochondria and contaminating cellular organelles that have overlapping densities with native lysosomes. Mouse liver tritosomes may also be prepared by our Custom Products team.
Our specially prepared rat liver tritosomes offer a complete and stoichiometrically correct test system demonstrating high lysosomal enzymatic activity and enrichment of lysosomal proteins with low contaminating activity from mitochondrial enzymes. Tritosomes can be used in preclinical drug development as a predictive in vitro test system to investigate catabolism of small- and large-molecule drugs fated to the endosome-lysosome pathway in humans; or to study lysosomal composition, function, and disease.
To ensure optimal results, our team has developed a tailored IgG catabolism protocol which has been optimized through characterization by immunoblot, enzymatic activity and protease content and includes technical tips for use of tritosomes. We have also formulated a specialized 10x catabolism buffer recommended for use with any in vitro assay using lysosomes or tritosomes.
Read more about the benefits of tritosome preparations in our Tritosomes FAQ or watch a webinar presentation discussing the use of lysosomal test systems in characterization of biologic drugs..
Prototypical Inducer-Treated Microsomes for Ex Vivo Induction Studies
Treating animals with various xenobiotics causes marked induction of liver microsomal CYP enzymes. We offer subcellular fractions from rat, non-human primate and canine cells treated with prototypical inducers to serve as positive controls for ex vivo enzyme induction studies or for metabolism assays to support data that indicates a specific CYP’s contribution to a compound’s metabolism.
These products are pooled from multiple animals to ensure good representation of the induction and to provide sufficient product availability. The following product information is included with each order of treated animal subcellular fractions:
- Cytochrome P450 content
- Cytochrome b5 content
- NADPH-cytochrome c reductase activity
- Activity of the inducible CYP enzyme
- Dosing regimen
- Animal husbandry conditions
|Product||Description||Volume||Protein Concentration||Induced CYP|
|R1063||Male IGS SD Rat Liver Microsomes – Clofibric Acid-Treated – 20mg/mL – Pool of 16||0.5mL||20 mg/mL||CYP4A|
|R1073||Male IGS SD Rat Liver Microsomes – 20mg/mL – Saline-Treated – Pool of 42||0.5mL||20 mg/mL||Control|
|R1078||Male IGS SD Rat Liver Microsomes – PB-Treated – 0.5mL @ 20mg/mL – Pool of 50||0.5mL||20 mg/mL||CYP2B|
|R1081||Male IGS SD Rat Liver Microsomes – PB and BNF-Treated – 20mg/mL||0.5mL||20 mg/mL||CYP 1A/2B|
|R1081.S9||Male IGS SD Rat Liver S9 – PB and BNF-Treated – 20mg/mL||1mL||20 mg/mL||CYP 1A/2B|
|R1083||Male IGS SD Rat Liver Microsomes – BNF-Treated – 20mg/mL||0.5mL||20 mg/mL||CYP1A|
|R1088||Male IGS SD Rat Liver Microsomes – Isoniazid-Treated – 20mg/mL||0.5mL||20 mg/mL||CYP2E|
|R1093||Male IGS SD Rat Liver Microsomes – Dex-Treated – 20mg/mL||0.5mL||20 mg/mL||CYP3A|
|R1098||Male IGS SD Rat Liver Microsomes – Corn Oil-Treated – 20mg/mL||0.5mL||20 mg/mL||Control|
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.
Don’t see what you need? Other preparations can be made available!
If you require subcellular fractions not available through our standard product offerings, custom preparations can be easily ordered to meet the specific needs of any study. Our designated Custom Products team regularly isolates and prepares subcellular fractions from more than 45 different species and has capabilities to meet needs unavailable through most vendors– non-standard rodent strains, farm animals, insects, precarious tissue isolations such as adrenal gland or jejunum– with over 40 characterization assays available to ensure adequate activity for data collection. See all of our Custom Preparations capabilities or get in touch with a specialist to find out how we can help.