A fast solution switching system with temperature control for single cell measurements

This article describes a perfusion system for biophysical single cell experiments at the physiological temperature. Our system regulates temperature of test solutions using a small heat exchanger that includes several capillaries. Water circulating inside the heat exchanger warms or cools test solutions flowing inside the capillaries. Temperature-controlled solutions are delivered directly to a single cell(s) through a multibarreled manifold that switches solutions bathing a cell in less than 1 s. This solution exchange is optimal for patch clamp, single-cell microamperometry, and microfluorometry experiments. Using this system, we demonstrate that exocytosis from pancreatic β cells and activation of TRPV1 channels are temperature sensitive. We also discuss how to measure local temperature near a single cell under investigation.

► We designed a local perfusion system for single cell biophysical experiments.
► A heat exchanger in the system warms or cools solution.
► Temperature variation between solutions applied to a cell was minimal (1 °C).
► Switch between solutions is quick (<1 s).
► Our system is suitable for patch clamp, Ca2+ imaging, and microamperometry with single cells.