Conventional Fluorescence Microscopy
Conventional Fluorescence Microscopy FigureUsing Fura-2FF, a Ca2+ indicator with relatively low affinity for Ca2+ and negligible affinity for Zn2+, and FluoZin-3, a Zn2+ indicator with high affinity for Zn2+ and no affinity for Ca2+, we are able to detect simultaneously the intracellular concentrations of Zn2+ and Ca2+ in cardiac myocytes.
Confocal Fluorescence Microscopy
Confocal Fluorescence Microscopy FigureAgain using FluoZin-2 as a Zn2+ indicator we are able to detect the spatial distribution of Zn2+ in live cardiac myocytes.
Small Amplitude Length Perturbation Analysis
Small Amplitude Length Perturbation Analysis FigureIn collaboration with cardiothoracic surgeons we have been able to examine the mechanical properties of human cardiac muscle. We use small amplitude length perturbations of skinned myocardium to detect visco-elastic properties of the muscle.
Small Amplitude Length Perturbation Analysis Figure 2Under relaxed and various Ca2+-activated conditions, small sinusoidal length perturbations, i.e., strains of <0.125% of initial length L0 (Panel A), are applied over a range of frequencies and the resulting tension (Panel B) is recorded. The elastic and viscous moduli are calculated for each frequency from the magnitudes of the in-phase (Panel C) and out-of-phase (Panel D) components of the tension, respectively, divided by the magnitude of the imposed strain. The elastic and viscous moduli are plotted against each other, and a characteristic “loop” arises as an indication of the sensitivity of acto-myosin crossbridge kinetics to mechanical perturbation (Panel E).