关键词: 毛细管电泳, 安培法检测, 单个细胞分析

Abstract: This Paper reports the use of capillary electrophoresis (CE)with electrochemical detection to first detect the amol amount of norepinephrine (NE) and epinephrine(E) in a single sympathetic nerve cell (diameter 15~25μm ,volume 2~5pL) of rat.The home-made CEwith electrochemical detection system consists of whole cell sampling, CEand amperometric detection.The whole cell sampling involves a micromanipulator, an inverted microscope and an in jection end of the capillary.To aid cell injection, the injection end of the capillary was etched to 100μm with hydrofluoric acid.The CEapparatus consists of 30 kVdc power supply , platinum wires and a fused-silica capillary (25μm i.d., 375μm i.d.,75 cm length) filled with 25 mmol/L MES buffer solution at pH 6.5 The amperometric detector used in this experiment was a carbon fiber microelectrode, The carbon fiber having a diame ter of 8μm and a length of 0.3mm,was inserted directly into the end of the electrophoresis capillary by micropositioner and microscope,The potential on the carbon fiber working electrode was controlled to 0.7Vvs.SCEreference electrode by a potentiostat.Currents produced were measured and recorded by a picoammeter and a recorder.Sympathetic ganglia were dissected from rats.After enzymolysis the cells were isolated.The injection end of the capillary was placed adjacent to the cell using micromanipulator under the microscope,The whole cell sampling was accomplished for CEby directly drawing a cell into the tip of a capillary with electroosmotic flow and lysing the cell inside the capillary as observed under the microscope, using a micromanipulator, All separations were performed in 25 mmol MESbuffer solution using 18 kV separation potential.The amperometric detector with microelectrode was used for detecting the neurotransmitters.The results in separation and detection the amol amount of NE and Ein a single sympathetic nerve cell using this system are satisfactory.

Key words: Capillary electrophoresis, Amperometric detection, Single cell analysis