The growth and viability of tobacco cells (Nicotiana tabacum L) immobilized in alginate or pectate were monitored during their cultivation by using two-dimensional fluorescence spectroscopy (2-D FS). The cell growth was followed via the fluorescence of amino acids in proteins. The correlation between the tryptophan fluorescence and the cell biomass inside the alginate beads was verified by comparison with the dry weight of the cells. The determination of biomass content or cell viability by measurement of the intensity of NAD(P)H fluorescence was found unsuitable. Cell viability was estimated by determination of cell esterase activity using fluorescein diacetate as a fluorogenic substrate. The fluorescence intensities of both fluorophores, tryptophan and fluorescein, were determined by scanning a 2-D FS spectrum of intact beads in front face cuvette. Using this technique the effect of organic solvent, dimethyl sulfoxide, on the growth and metabolic activities of cells within the beads was evaluated. While 4% DMSO was tolerated by cells, 6% DMSO led to the cell destruction.
Use of two-dimensional fluorescence spectroscopy for monitoring of the effect of dimethyl sulfoxide on the growth and viability of immobilized plant cells