Two-dimensional thermal analysis for freezing of plant and animal cells by high-speed microscopic IR camera

Using a high speed IR camera for temperature sensor is a powerful new tool for thermal analysis of bio-cells. In this study we propose two-dimensional thermal analysis by means of a high speed IR camera with a microscopic lens, and applied it to the analysis of freezing of plant and animal cells. The latent heat on the freezing of super cooled onion epidermal cell was randomly observed by a unit cell size, one by one, under a cooling rate of 80degreesC/min with a spatial resolution of 7.5 mum. The freezing front of ice formation and the thermal diffusion behavior of generated latent heat are analyzed. As a result it is possible to determine simultaneously the inter-cellular/intra-cellular temperature distribution, the growing speed of freezing front in a single cell, and the thermal diffusion in the freezing process of living tissue. A new measuring system presented here will be significant in the measurement technique of thermal property of bio-cells. Temperature wave technique for the measurement of in-plane thermal diffusivity was also applied to the cell systems.