Recent advances of microcalorimetry for studying cellular metabolic heat

Cellular metabolic heat (ΔPM) is produced from intracellular reactions, carrying information about particular processes thus indicating the status of organisms. ΔPM originating from a single cell is at pW level, making its determination based on the calorimetry technique challenging. Microcalorimetry, evolved from original calorimetry, provides an opportunity to look inside the cell by monitoring ΔPM at single-cell level due to its high resolution. In this review, we discuss the microcalorimetry-based techniques utilized to measure ΔPM, as well as its extended applications. We first introduce the characterization of microcalorimeters and propose potential methods to improve the performance of these devices. Then we focus on ΔPM measurements using microcalorimeters both in microorganisms and mammalian cells. We also review the applications of ΔPM measurements for fundamental metabolism research and drug susceptibility tests. The measurement of ΔPM at single-cell level is challenging shedding light on cellular processes and enhance our knowledge in this field.