Identification of Multiple Compartments of Dopamine in a Single Cell by CE with Scanning Electrochemical Detection

A method is described for the direct identification of dopamine from two separate vesicular compartments of a fully developed neuron in Planorbis corneus by capillary electrophoresis with scanning electrochemical detection. By manipulating the lyse time of the neuron after it is injected on the capillary, the two vesicular compartments are observed as two individually resolved peaks. Scanning electrochemical detection allows voltammetry to be obtained as the peaks elute in order to confirm their identity. Quantitation was accomplished through the use of calibration curves. The average amount of dopamine present was found to be ∼400 fmol. Dopamine concentrations were also determined and compared favorably with those of previous experiments on P. corneus.