Thermal noise in cells. A cause of spontaneous loss of cell function.

Background noise due to random thermal perturbations of molecules has a disruptive effect on all information handling systems, including cells and organisms. This thermal noise appears to be largely responsible for the spontaneous loss of proliferative cells in cell cultures. The rates at which proliferative cells are lost as a result of heat injury, in cultured hamster cells, have been measured at high temperatures and extrapolated down to 37 C. This gives an expected 0.2% loss per hour due to thermal injury at physiologic temperature. That such a loss does in fact occur can be shown by comparing cell generation time with population doubling time, when these cells are growing at physiologic temperatures. Apparently, internal thermal noise presents a primary hazard to the reliable functioning of the cell quite apart from the insults it receives from its external environment.