Fiber-optic chemical sensing has been demonstrated with a side-polished single-mode optical fiber, evanescently coupled to chemically sensitive Langmuir-Blodgett (LB) overlay waveguides. The sensors exhibit a channel-dropping response centered on a wavelength that is dependent on the thickness and the refractive index of the overlay waveguide. It has been shown that pH-sensitive organic dyes pr...

In the current study, we investigated pharmacological side effects and signal-to-noise ratios (SNRs) of two commonly used voltage-sensitive dyes (VSDs): the blue dye RH-1691 (1 mg/ml) and the red dye di-4-ANEPPS (0.1 mg/ml), applied in vivo to the rat barrel cortex. Blue dyes are often favored over red dyes in in vivo studies due to their apparent superior SNR, partly because their fluorescence...

SUMMARY Rhizobium lipochitooligosaccharide signal molecules stimulate multiple responses in legume host plants, including changes in host gene expression, cell growth, and mitoses leading to root nodule development. The basis for signal transduction in the plant is not known. We examined cytoplasmic free calcium in host root hairs using calcium-sensitive reporter dyes. Image analysis of injecte...

A simple and sensitive high-performance liquid chromatography (HPLC) analytical method for the simultaneous determination of six Sudan dyes (Sudan Red G, Sudan I, Sudan II, Sudan III, Sudan Red 7B, Sudan IV) in animal tissues and eggs was developed. Samples were extracted with acetonitrile followed by a cleanup using a C(18) solid-phase extraction column. Chromatographic separation was achieved...

Fluorescence imaging is an attractive method for monitoring neuronal activity. A key challenge for optically monitoring voltage is development of sensors that can give large and fast responses to changes in transmembrane potential. We now present fluorescent sensors that detect voltage changes in neurons by modulation of photo-induced electron transfer (PeT) from an electron donor through a syn...

This protocol describes the loading of individual cells with fluorescent probes via patch pipettes. The patch-clamp methodology has been successfully used for single-cell dye labeling in cultured neurons, brain slices, and in vivo preparations. A broad range of dyes can be used with this loading technique. Markers for morphological reconstruction (e.g., Lucifer yellow); ion-sensitive indicator ...

The photothermal effect is the generation of heat by molecules or particles upon high-energy laser irradiation, and near-infrared absorbers such as gold nanoparticles and organic dyes have a range of potential photothermal applications. The favourable photothermal properties of thiophene-functionalised croconaine dyes were recently discovered. The synthesis and properties of novel croconaine ro...