Improvement on frozen mitochondria bioassay: a methodological remark.

The protocol for the bioassay with the mitochondria of beef heart frozen at -22 °C, (developed by Iero, Manente, Bragadin and Perin, in Chemosphere, 52, 2003) requires that the reaction cell is thermostatically controlled at 25 °C. This value was chosen because it is used as a reference for the state environmental standard (Standard Ambient Temperature and Pressure, SATP). The choice is not, therefore, been supported by assessments on the effectiveness of the test at this temperature, but was dictated by the practice of reporting results to a standard temperature value. Finally, it was decided to make a comparison between the working temperature of 25 °C and the 37 °C one, chosen as close to cattle body temperature (estimated to be 38.6 °C), then "normal" working temperature for mitochondria extracted from heart.