Temperature-controlled microscopy for imaging living cells: apparatus, thermal analysis and temperature dependency of embryonic elongation in Caenorhabditis elegans.

A new experimental apparatus for temperature-controlled microscopy has been developed for the study of the temperature dependency of developmental processes in the nematode Caenorhabditis elegans. However, the application of this apparatus is rather general and can be used for a wide range of temperatures between - 10 and 90 degrees C. The new apparatus is easy to use, inexpensive, simple to construct, and is designed for precise temperature control of oil-immersion microscopy using epifluorescence. Thermal analysis of the experimental apparatus shows the effects of each of its components, as well as the effects of uncertainty in temperature measurements. Finally, results of this study indicate that: (i) embryos incubated and imaged at temperatures of 8 degrees C and below do not elongate; (ii) the initial elongation rate is strongly temperature-dependent between 9 and 25 degrees C.