CASTDan:Abstract22
Kostov, Y., Entcheva E., Tchernev E., Tung L., (2004) Fluorescence Imaging of Electrical Activity in Cardiac Cells Using An All-Solid-State System. IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING. VOL. 51, NO. 2
Abstract
Tracking spatial and temporal determinants of cardiac
arrhythmogenesis at the cellular level presents challenges to
the optical mapping techniques employed. In this paper, we describe
a compact system combining two nontraditional low-cost solutions
for excitation light sources and emission filters in fluorescence
measurements of transmembrane potentials, Vm, or intracellular
calcium, [Ca2+]i in cardiac cell networks. This is the first
reported use of high-power blue and green light emitting diodes
(LEDs), to excite cell monolayers stained withVm- (di-8-ANEPPS)
or [Ca2+]i – (Fluo-3) sensitive dyes. In addition, we use simple
techniques for fabrication of suitable thin emission filters with uniform
properties, no auto-fluorescence, high durability and good
flexibility for imagingVm or [Ca2+]i . The battery-operated LEDs
and the fabricated emission filters, integrated with a fiber-optic
system for contact fluorescence imaging, were used as tools to characterize
conduction velocity restitution at the macro-scale. The versatility
of the LEDs for illumination is further emphasized through
1) demonstration of their usage for epi-illumination recordings at
the single-cell level, and 2) demonstration of their unique high-frequency
light modulation ability. The LEDs showed excellent stability
as excitation light sources for fluorescence measurements; acceptable
signal-to-noise ratio and negligible cell photodamage and
indicator dye photobleaching were observed.
