Rat ventricular cardiac myocytes were isolated from hearts injected
with the GFP plasmid or with the tagged siRNA on a Langendorff
apparatus as described previously [41]. The isolated myocytes from
the siRNA injected hearts were loaded with the calcium dye Fura2 for
30 min at room temperature. Cells were field stimulated at 1 Hz
(20 V), and simultaneously illuminated at 340 nm and 380 nm using
a xenon arc bulb light. Fura2 fluorescence emitted at 510 nm was
recorded using IonOptix acquisition software (IonOptix system, Hilton,
USA).