Phenotype study techniques

With radiolabeled drug in hand much more detailed reaction phenotyping studies can be preformed. This is especially the case with compounds that are poorly metabolized in vitro and where there is difficulty in accurately measuring parent disappearance. Radiolabeling allows quantitation of all metabolites formed even in small quantity. The same in vitro techniques are used as described above, but this time with accurate quantitation of all components. There are methods that allow more rapid phenotyping studies, either through the use of authentic metabolite standards and LC—MS or a combination of radiolabeling and LC—MS. 

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