RT Journal Article
SR Electronic
T1 SiCTeC: an inexpensive, easily assembled Peltier device for rapid temperature shifting during single-cell imaging
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.05.29.123166
DO 10.1101/2020.05.29.123166
A1 Benjamin D. Knapp
A1 Lillian Zhu
A1 Kerwyn Casey Huang
YR 2020
UL http://biorxiv.org/content/early/2020/05/29/2020.05.29.123166.abstract
AB Single-cell imaging, combined with recent advances in image analysis and microfluidic technologies, have enabled fundamental discoveries of cellular responses to chemical perturbations that are often obscured by traditional liquid-culture experiments. Temperature is an environmental variable well known to impact growth and to elicit specific stress responses at extreme values; it is often used as a genetic tool to interrogate essential genes. However, the dynamic effects of temperature shifts have remained mostly unstudied at the single-cell level, due largely to engineering challenges related to sample stability, heatsink considerations, and temperature measurement and feedback. Additionally, the few commercially available temperature-control platforms are costly. Here, we report an inexpensive (<$110) and modular Single-Cell Temperature Controller (SiCTeC) device for microbial imaging, based on straightforward modifications of the typical slide-sample-coverslip approach to microbial imaging, that controls temperature using a ring-shaped Peltier module and microcontroller feedback. Through stable and precise (±0.15 °C) temperature control, SiCTeC achieves reproducible and fast (1-2 min) temperature transitions with programmable waveforms between room temperature and 45 °C with an air objective. At the device’s maximum temperature of 89 °C, SiCTeC revealed that Escherichia coli cells progressively shrink and lose cellular contents. During oscillations between 30 °C and 37 °C, cells rapidly adapted their response to temperature upshifts. Furthermore, SiCTeC enabled the discovery of rapid morphological changes and enhanced sensitivity to substrate stiffness during upshifts to nonpermissive temperatures in temperature-sensitive mutants of cell-wall synthesis enzymes. Overall, the simplicity and affordability of SiCTeC empowers future studies of the temperature dependence of single-cell physiology.