Double-isotope dansyl microassay

The Double-Isotope Dansyl Microassay for Measurement of Cerebral Amino Acids... 

Calculation of Results Using Double Isotope Dansyl Microassay... 

The double-isotope dansyl microassay has also been used to measure release of amino acids from brain preparations in vitro (Snodgrass and Iversen, 1973). Rat cortical tissue was chopped using a Mcllwam chopper and suspended in Krebs-bi-carbonate-glucose medium. Electrical stimulation was applied and, following superfusion, the medium was changed for a Krebs-bicarbonate buffer containing 55 mM KCl. In this way,... 

The major disadvantage of the double-isotope dansyl microassay IS its requirement for considerable manual manipulation. 

Values for amino acid content of rat brain regions using the double-isotope dansyl microassay are comparable to those obtained using other techniques, such as the amino acid autoanalyzer... 

Another methodology described in this volume is the use of l-dimethylaminonaphthalene-5-sulfonyl chloride (dansyl chloride) in the estimation of ammo acid levels. A double-isotope dansyl microassay for cerebral amino acids is described in detail, including the use of thin-layer chromatographic techniques for the separation of the dansyl derivatives The usefulness of the double-isotope labeling in overcoming problems inherent m the dansyl procedure is discussed by the author. Apart from a liquid scintillation counter, which is available in most laboratories, no sophisticated or expensive equipment is required for the microassay On the other hand, extensive and time-consuming manual manipulations are required for the procedure. 

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