In situ fiber-optical monitoring of cytosolic calcium in tissue explant cultures

TL;DR

This paper introduces a fiber-optic fluorescence lifetime method for real-time, in situ monitoring of cytosolic calcium levels in tissue explants, overcoming autofluorescence interference with high sensitivity and rapid response.

Contribution

It presents a novel fiber-optic fluorescence lifetime technique for in situ cell activity monitoring, capable of detecting small calcium changes in tissue cultures.

Findings

Detected calcium concentration changes as small as 2.5 nM

Achieved monitoring time resolution of less than 1 second

Successfully monitored calcium in tissue explants using a simple optical setup

Abstract

We present a fluorescence-lifetime based method for monitoring cell and tissue activity in situ, during cell culturing and in the presence of a strong autofluorescence background. The miniature fiber-optic probes are easily incorporated in the tight space of a cell culture chamber or in an endoscope. As a first application we monitored the cytosolic calcium levels in porcine tracheal explant cultures using the Calcium Green-5N (CG5N) indicator. Despite the simplicity of the optical setup we are able to detect changes of calcium concentration as small as 2.5 nM, with a monitoring time resolution of less than 1 s.