Analytical and Bioanalytical Chemistry

, Volume 387, Issue 1, pp 97–105

A multichannel native fluorescence detection system for capillary electrophoretic analysis of neurotransmitters in single neurons

  • T. Lapainis
  • C. Scanlan
  • S. S. Rubakhin
  • J. V. Sweedler
Original Paper

Abstract

A laser-induced native fluorescence detection system optimized for analysis of indolamines and catecholamines by capillary electrophoresis is described. A hollow-cathode metal vapor laser emitting at 224 nm is used for fluorescence excitation, and the emitted fluorescence is spectrally distributed by a series of dichroic beam-splitters into three wavelength channels: 250–310 nm, 310–400 nm, and >400 nm. A separate photomultiplier tube is used for detection of the fluorescence in each of the three wavelength ranges. The instrument provides more information than a single-channel system, without the complexity associfated with a spectrograph/charge-coupled device-based detector. With this instrument, analytes can be separated and identified not only on the basis of their electrophoretic migration time but also on the basis of their multichannel signature, which consists of the ratios of relative fluorescence intensities detected in each wavelength channel. The 224-nm excitation channel resulted in a detection limit of 40 nmol L−1 for dopamine. The utility of this instrument for single-cell analysis was demonstrated by the detection and identification of the neurotransmitters in serotonergic LPeD1 and dopaminergic RPeD1 neurons, isolated from the central nervous system of the well-established neurobiological model Lymnaea stagnalis. Not only can this system detect neurotransmitters in these individual neurons with S/N>50, but analyte identity is confirmed on the basis of spectral characteristics. 

Keywords

Capillary electrophoresis Laser-induced native fluorescence detection Single-cell analysis Dopamine Lymnaea stagnalis 

Abbreviations

5-HT

serotonin

ASW

artificial sea water

CE

capillary electrophoresis

CNS

central nervous system

CW

continuous wavelength

DA

dopamine

EC

electrochemical detection

LINF

laser-induced native fluorescence

MCC

metacerebral cells

PMT

photomultiplier tube

Trp

tryptophan

Tyr

tyrosine

OA

octopamine

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • T. Lapainis
    • 1
  • C. Scanlan
    • 1
  • S. S. Rubakhin
    • 1
  • J. V. Sweedler
    • 1
  1. 1.Department of Chemistry and the Beckman InstituteUniversity of IllinoisUrbanaUSA

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