The dynamics of mitochondrial [Ca 2+ ] ([Ca 2+ ] M) plays a key role in a variety of cellular processes. The most important methods available to monitor [Ca 2+ ] M are fluorescent dyes such as rhod-2 and specifically targeted proteins such as aequorin or pericam. However, significant discrepancies, both quantitative and qualitative, exist in the literature between the results obtained with diff...

BACKGROUND The fluorescence induced by polarized light sources, such as the lasers that are used in flow cytometry, is often polarized and anisotropic. In addition, most optical detector systems are sensitive to the direction of polarization. These two factors influence the accuracy of fluorescence intensity measurements. The intensity of two light sources can be compared only if all details of...

Voltage-sensitive fluorescent dyes have become a major tool in cardiac and neuro-electrophysiology. Achieving high signal-to-noise ratios requires increased illumination intensities, which may cause photobleaching and phototoxicity. The optimal range of illumination intensities varies for different dyes and must be evaluated individually. We evaluate two dyes: di-4-ANBDQBS (excitation 660 nm) a...

Visualization and quantification of lipid order is an important tool in membrane biophysics and cell biology, but the availability of environmentally sensitive fluorescent membrane probes is limited. Here, we present the characterization of the novel fluorescent dyes PY3304, PY3174 and PY3184, whose fluorescence properties are sensitive to membrane lipid order. In artificial bilayers, the fluor...

Imaging activity of neurons in intact brain tissue was conceived several decades ago and, after many years of development, voltage-sensitive dyes now offer the highest spatial and temporal resolution for imaging neuronal functions in the living brain. Further progress in this field is expected from the emergent development of genetically encoded fluorescent sensors of membrane potential. These ...

Neutrophils are crucial to host innate defense and, consequently, constitute an important area of medical research. The phagosome, the intracellular compartment where the killing and digestion of engulfed particles take place, is the main arena for neutrophil pathogen killing that requires tight regulation. Phagosomal pH is one aspect that is carefully controlled, in turn regulating antimicrobi...

Nakamura, Hakobu (Konan University, Kobe, Japan). Acriflavine-binding capacity of Escherichia coli in relation to acriflavine sensitivity and metabolic activity. J. Bacteriol. 92:1447-1452. 1966.-Inheritance of the acriflavine resistance gene by an acriflavine-sensitive strain of Escherichia coli K-12 resulted in a reduction in the cellular accumulation of acriflavine and other basic dyes, but ...

Neurons communicate by using electrical signals, mediated by transient changes in the voltage across the plasma membrane. Optical techniques for visualizing these transmembrane potentials could revolutionize the field of neurobiology by allowing the spatial profile of electrical activity to be imaged in real time with high resolution, along individual neurons or groups of neurons within their n...

Organic dyes are useful tools for sensing cellular activities but unfavorable in single-molecule imaging, whereas quantum dots (QDs) are widely applied in single-molecule imaging but with few sensing applications. Here, to visualize cellular activities by monitoring the response of a single probe in living cells, we propose a bottom-up approach to generate nanoprobes where four organic dyes are...