Amines & Their Metabolites (NEUROMETHODS) (Neuromethods 2 by Alan A. Boulton, Glen B. Baker

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2. Procedures Catecholamme content of the brain decreases durmg the postmortem perrod For thus reason, following sacrifice, tissue is rapidly removed and dissected on dry ice, wrapped In preweighed alummum forl, and frozen on dry ice. Trssue is stored at -70°C until time of assay. 1. 3 mL acidified n-butanollsodium metabisulfite/EDTA. 3 mL of this homogenate is then used for the extraction procedure. OlN). 3 mL of acidified n-butanol mixture is added, and the mixture shaken 10 min. 0 mL distilled water for 5 mm and centrifuged (lOOOg, 5 mm).

Although such methods are very sensitive, they are not without problems. Quantitation is often difficult because of the occurrence of undesirable side reactions, variability m the degree to which individual compounds react, and variability caused by changes m the ratio of reagent to substrates. Osborne has stated that the identities and structures of all substances to be dansylated must be known before quantitatlon can be carried out. Because of these limitations, Internal standards can be used only when the ammo acid and amine contents of all samples are not significantly different.

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