single-photon

ANNINE-6plus is a water soluble voltage sensitive dye (also called potentiometric dyes). This compound was developed at the Max Planck Institute for Biochemistry in Germany. It is used to optically measure the changes in transmembrane voltage of excitable

The rapid, selective, and sensitive sensing of thiols is important in diverse areas of research. This thiofluor 623 responds upon exposure to thiols with an increase in fluorescence intensity of up to 120-fold. The response is selective for thiols and occurs in aqueous media. In the absence of thiols, the probe is essentially non-fluorescent; thiols cause cleavage of the probe, generating a fluorophore with an absorption maximum of 563 nm and emission at 623 nm. The fluorescence quantum yield of the cleaved product, generated in response to thiols, increases in more viscous media, suggesting ideal performance in biological systems and applicability to single-molecule or 2-photon sensing schemes. The thiofluor 623 is cell-permeable and reacts selectively with intracellular thiols. The pseudo-first order rate constant (kobs) depends on substrate (e.g., 2.1 x 10-3 s-1 for cysteine, 2.0 x 10-5 s-1 for human serum albumin).

SBFI AM is a membrane-permeant, fluorescent Na+ indicator dye. It is selective for Na+ over K+ with Kd values of 20 and 120 mM for these ions, respectively. [1]Increasing concentration of Na+ increases the ratio of excitation efficiency at 330-345 nm to that at 370-390 nm with emission collected at 450-550 nm. [1] Therefore, ratio fluorometry and imaging can be performed with the same wavelengths. SBF AM is suitable for single intracellular dye injection and is typically used for high-resolution measurements of Na+ concentration in intact tissue through two-photon confocal imaging.[2]