62796-23-0

Usage

Uses

Used in Cellular and Molecular Biology:
MEROCYANINE 540 is used as a sensitive probe for [membrane potential] for [detecting changes in the electrical potential across cell membranes]. This application is crucial in understanding cellular processes and functions.
Used in Flow Cytometry:
MEROCYANINE 540 is used as a selective staining agent for [immature hemopoietic cells] for [identifying and distinguishing these cells from mature cells in flow cytometry]. This helps in studying the development and differentiation of blood cells.
Used in Neuroscience:
MEROCYANINE 540 is used as a fluorescent axonal stain for [visualizing and tracing neuronal structures]. This application aids in the study of neuronal connectivity and the organization of neural circuits.

InChI:InChI=1/C26H33N3O6S2.Na/c1-3-5-16-28-24(30)20(25(31)29(26(28)36)17-6-4-2)12-7-10-15-23-27(18-11-19-37(32,33)34)21-13-8-9-14-22(21)35-23;/h7-10,12-15H,3-6,11,16-19H2,1-2H3,(H,32,33,34);/q;+1/p-1

Relevant academic research and scientific papers

Photoisomerization of a sterically constrained merocyanine dye

A particular concern regarding the photophysical properties of merocyanine 540 derivatives, and related cyanine dyes, involves identifying which double bond in the central polyenic bridge undergoes light-induced isomerization. In order to address this issue we have synthesized a novel merocyanine dye in which the first double bond is built into a cyclic structure that prevents isomerization at this site. Contrary to expectations, the dye photoisomerizes with reasonable efficiency, such that the quantum yields of fluorescence and intersystem crossing to the triplet manifold are kept small. For this dye, isomerization must take place at the central double bond. It is further shown that the strategy of inserting bulky or constraining groups into the polyenic bridge is not a viable approach for the development of highly fluorescent merocyanine dyes.

Spin-orbital coupling effects on the photophysical properties and photocytotoxicity of merocyanine dyes

A series of merocyanine dyes possessing different heteroatoms in the terminal aromatic and barbiturate units has been synthesized The nature of the heteroatom does not affect the all-trans alignment of the central polyenic bridge, as demonstrated by 1H NMR spectroscopy. There are pronounced changes, however, in the photophysical properties of the individual molecules due to structural, electronic and spin-orbital coupling effects induced by the heteroatoms. In particular, it has been possible to vary the quantum yield for formation of the lowest-energy triplet excited state by more than two orders of magnitude. Quantum yields and lifetimes for fluourescence and photoisomerization are also affected by the choice of heteroatom. Despite the major changes in triplet yield that take place upon insertion of heteroatoms displaying strong spin-orbital coupling effects (e.g., Se) the efficacy for light-induced cytotoxicity towards cancer cells shows but a modest dependence on the structure of the dye. There is a reasonably good correlation between triplet yield and the rate of light-induced cell killing as might be expected for a mechanism based on intermediate generation of singlet molecular oxygen. However, equally good correlations exist between cell-killing performance and both relative lipophilicity and the rate at which the dye penetrates into intact biological cells.