Microcalorimetric studies of hybridoma cells

In the present study, overall metabolism has been estimated in hybridoma cells by microcalorimetric measurement. Heat production rate was found to be 30-50 pW/cell at cell concentrations 0.65-4.5 x 10(5)/ml. High cell concentrations (1 x 10(6) cells/ml) caused unstable power-curves with an initial high peak and a rapid declining phase, whereas low cell concentrations (0.6-4.5 x 10(5) cells/ml) produced steady-state power-curves. Oxygen consumption was found to range between 1.5-6.1 x 10(-5) mol 02/cell/min, corresponding to about 80% of the total metabolic activity. The metabolic inhibitors sodium fluoride (50 nM), sodium azide (160 mM) and rotenone (0.1 mM) caused a reduction in overall cell metabolism of 60, 55 and 40% respectively.