DETERMINATION OF CALCIUM CONTENT IN INDIVIDUAL BIOLOGICAL CELLS BY INDUCTIVELY-COUPLED PLASMA-ATOMIC EMISSION-SPECTROMETRY

A cell analyzer is described which can continuously determine the calc ium content in individual biological cells by inductively coupled plas ma atomic emission spectrometry in real time. A cell suspension in eth anol (70% in water) is sprayed by a concentric nebulizer, and the drop lets containing cells are dried in a drying chamber. The dried cells d ispersed in air are directly introduced into the plasma to determine t he calcium by emission spectrometry. Each flash derived from each cell in the plasma is converted into an electric pulse corresponding to th e calcium content in the cell, and the heights of the pulses are measu red by a pulse height analyzer. To calibrate this system, monodisperse calcium acetate aerosols are prepared by a vibrating orifice monodisp erse aerosol generator. The determined calcium contents in several mam malian cell samples range from 0.057 to 0.27 pg. The detection limit o f the present system is similar to 0.01 pg of calcium in a cell.