Nanocalorimeter for measuring the heat production in mitochondria

Measurements of energy transformation and dissipation in mitochondria by the calorimetric method were carried out in the second half of the last century. However, to date no specialized calorimeter has been developed for this purpose. Selection of compounds providing uncoupleted mitochondrial respiration without damaging the respiratory chain components, for use in pharmaceutical compositions of drugs, development of new neuroprotectors, nefroprotectors require precise measurements of heat release by different mitochondrial uncouplers of oxidative phosphorylation. A capillary differential nanocalorimeter for studying energy transformation and dissipation in the mitochondria has been created in the IBI RAS. The instrument meets the above requirements. The principal advantage of the nanocalorimeter is that it has thermal bridges for the thermostatingthe mitochondria injection. In the thermal bridges mitochondria acquire the desired temperature for a few seconds. Mitochondria are introduced uniformly along the entire length of the calorimeter chamber by means of a dispensing needle. This provides mixing of mitochondria with the sample without great energy consumption and thermal noise. Precision measurements of thermal power of the processes of transformation and dissipation of energy in the mitochondria are carried out at an absolute error less than 50 nW.