What is in S9 fraction?

S9 fraction is conventionally prepared by homogenization of liver in isotonic potassium chloride (0.15 M KCl) at a rate of 1 g wet tissue per 3 mL and then separated by centrifugation at 9000 g.

What is S9 mixture?

S9 fraction is a mixture of unfractionated microsomes and cytosol containing a wide variety of drug-metabolizing enzymes and is commonly used as a preferred test system in several in vitro ADME (Absorption, Distribution, Metabolism, and Excretion) studies investigating phase I and phase II metabolism of a drug compound …

What does S9 extract do?

S9 is a crude liver enzyme extract that can, under certain conditions, convert materials without any genotoxic activity to active genotoxic entities. The chemical process involved may be different for different materials.

What are liver microsomes?

Human liver microsomes contain a wide variety of drug-metabolizing enzymes and are commonly used to support in vitro metabolism studies, such as reaction phenotyping, metabolic stability, metabolite identification (MetID), and enzyme inhibition.

What is S9 liver extract?

S9 is a liver extract (e.g. rat, hamster) that contains active liver enzymes (P450 activity) simulating the hepatic metabolism in in vitro assays. The P450 activity in S9 can be increased through induction with pure chemicals like Aroclor1254 or Phenobarbital.

Where are microsomes found?

Microsomal enzymes are typically found in the endoplasmic reticulum of hepatocytes. Microsomes are fragments of endoplasmic reticulum and attached ribosomes that are isolated together when homogenized cells are centrifuged.

What is S9 mix in Ames test?

Applications. The S9 fraction has been used in conjunction with the Ames test to assess the mutagenic potential of chemical compounds. Chemical substances sometimes require metabolic activation in order to become mutagenic.

Why S9 extract is used in Ames test?

Salmonella typhimurium is a prokaryote, therefore it is not a perfect model for humans. Rat liver S9 fraction is used to mimic the mammalian metabolic conditions so that the mutagenic potential of metabolites formed by a parent molecule in the hepatic system can be assessed; however, there are differences in metabolism …

What do microsomes do?

Microsomes are used to mimic the activity of the endoplasmic reticulum in a test tube and conduct experiments that require protein synthesis on a membrane. They provide a way for scientists to figure out how proteins are being made on the ER in a cell by reconstituting the process in a test tube.

What enzymes are in liver microsomes?

Liver microsomes, as vesicles of the hepatocyte endoplasmic reticulum, contain membrane phase I enzymes namely CYPs, flavine-containing monooxygenases (FMO), esterases, amidases, and epoxide hydrolases, and also the phase II enzymes such as UGTs.

What does S9 do in Ames test?

How are microsomes formed?

Microsomes are artificial structures derived from pieces of endoplasmic reticulum (ER) formed during tissue homogenization. They are prepared by differential centrifugation at 10,000 and 100,000 × g and contain cytochrome P450 enzymes (CYPs), but do not contain soluble enzymes.

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