A microscopy-compatible temperature regulation system for single-cell phenotype analysis - demonstrated by...

Area of Science:

• Biotechnology
• Ecotoxicology
• Microfluidics
• Cellular Physiology

Background:

• Coral reefs face thermal stress, impacting symbiotic algae (Symbiodinium).
• Understanding Symbiodinium's thermal sensitivity is crucial for coral resilience.
• Existing methods lack precise control over temperature exposure for cellular studies.

Purpose of the Study:

• To develop and demonstrate a programmable heat-stage for in situ microscopy.
• To investigate the spatiotemporal effects of temperature on Symbiodinium photophysiology.
• To explore the relationship between temperature exposure dynamics and Symbiodinium acclimatization.

Main Methods:

• Fabrication of a heat-stage with integrated Joule heaters and resistance temperature detectors (RTDs).
• Custom software for precise programming of temperature profiles (gradients and time-varying).
• In situ chlorophyll fluorometry to monitor single-cell photophysiology of Symbiodinium exposed to controlled temperatures.

Main Results:

• Demonstrated accurate delivery of biologically relevant temperature profiles to microfluidic devices.
• Revealed that Symbiodinium photophysiology is influenced by temperature exposure duration, magnitude, and strain.
• Identified cell acclimatization under prolonged (6h) but not short (15min) temperature exposures.

Conclusions:

• The programmable heat-stage offers a versatile tool for single-cell resolution research on thermal interdependencies.
• Findings advance understanding of Symbiodinium thermal sensitivity and its implications for coral thermal tolerance.
• The technology holds potential for broader applications in biotechnology and ecotoxicology.