Intracellular temperature mapping with afluorescent polymeric thermometer andfluorescence lifetime imaging microscopy

摘要

Cellular functions are fundamentally regulated by intracellular temperature, which influencesbiochemical reactions inside a cell. Despite the important contributions to biological and medicalapplications that it would offer, intracellular temperature mapping has not been achieved. Herewe demonstrate the first intracellular temperature mapping based on a fluorescent polymericthermometer and fluorescence lifetime imaging microscopy. The spatial and temperatureresolutions of our thermometry were at the diffraction limited level (200nm) and 0.18–0.58°C. The intracellular temperature distribution we observed indicated that the nucleus andcentrosome of a Cos7 cell, both showed a significantly higher temperature than the cytoplasmand that the temperature gap between the nucleus and the cytoplasm differed depending onthe cell cycle. The heat production from mitochondria was also observed as a proximal localtemperature increase. These results showed that our new intracellular thermometry coulddetermine an intrinsic relationship between the temperature and organelle function.