AJP - Cell Physiology, Vol 263, Issue 4 C723-C728, Copyright © 1992 by American Physiological Society
Intracellular signal transduction in four dimensions: from molecular design to physiology
R. Y. Tsien
Howard Hughes Medical Institute, Department of Pharmacology, University of California, San Diego, La Jolla 92093-0647.
Designed fluorescent indicators are the basis for a major new technique in
cell physiology, the quantitative measurement and dynamic imaging of
intracellular concentrations of important ions and messengers such as Ca2+,
Na+, H+, and adenosine 3',5'-cyclic monophosphate. Molecular engineering
has now produced indicators with quite good selectivity and sensitivity for
these analytes. In many cases, these probes can be introduced into large
populations of cells by means of membrane-permeant chemical derivatives, so
that the plasma membrane need never be disrupted or physically breached at
any point. Like many other optical microscopic techniques, fluorescent
indicators are readily applied to study living cells and tissues, with an
unparalleled combination of spatial and temporal resolution. They offer one
of the few methods for continuous nondestructive monitoring of dynamic
intracellular biochemistry and signal transduction in single cells or
subregions of cells.
