Alcohol thermometer to give a background for reading the scale. The range of usefulness of the thermometer is set by the boiling point of the liquid used. In the case of the ethanol-filled thermometer, the upper limit for measurement is 78 °C (172.4 °F), which makes it useful for measuring daytime, nighttime and body temperatures, although not for anything much hotter than these. Ethanol-filled thermometers are used in preference to mercury for meteorological measurements of minimum temperatures and can be used down to −70 °C (-94 °F). The physical limitation of the ability of a thermometer to measure low temperature is the
IbpB thermometer IbpB thermometer The IbpB thermometer is an RNA thermometer element found in the "ibpAB" operon. The operon contains two heat-shock genes, encoding inclusion body binding proteins A and B (IbpA/B), and is the most drastically upregulated operon under heat-shock in "Escherichia coli". "IbpA" is regulated by a ROSE element found in its 5' UTR, while "IbpB" has its own heat-sensitive cis-regulatory element. The activity of this thermoregulator was confirmed "in vitro" but was not found "in vivo", suggesting more complicated operon regulation exists in bacterial cells. The IbpB protein, whose expression is regulated by the IbpB thermometer, is 48% identical