Multicolor Labeling of Cell Nucleus with DNA-Binding Dyes
The nucleus is the largest cellular organelle in animals. In mammalian cells, the average diameter of the nucleus is approximately 6 µm, which occupies about 10% of the total cell volume. Nucleus contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these chromosomes are the cell's nuclear genome. The function of the nucleus is to maintain the integrity of these genes and to control the activities of the cell by regulating gene expression, therefore, the nucleus is the control center of the cell. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm, and the nucleoskeleton. Movement of large molecules through the pores is required for both gene expression and the maintenance of chromosomes.
Labeling the Nuclei of Live Cells
Nuclear Green™ LCS1, Nuclear Orange™ LCS1, Nuclear Red™ LCS1 and Nuclear Yellow are fluorogenic, DNA-selective and cell-permeant dyes for analyzing DNA content in living cells. The fluorescence of these dyes is significantly enhanced upon binding to DNA. They can be used in fluorescence imaging, microplate and flow cytometry applications. These DNA-binding dyes might be used for multicolor analysis of live cells with proper filter sets.
Image of live HeLa cells stained with Nuclear Green™ LCS1. The mitochondria of live HeLa cells were stained with red fluorescence Cell Navigator® Mitochondrion Staining Kit.
Our recently developed Nuclear Blue™ LCS1 is a fluorogenic, DNA-selective and cell-permeant dye for analyzing DNA content in living cells. The Nuclear Blue™ LCS1 has its blue fluorescence significantly enhanced upon binding to DNA. It can be used in fluorescence imaging, microplate and flow cytometry applications. It is well excited by violet laser at 405 nm, and emits blue/cyan fluorescence light with an emission maximum at ~440 nm, and provides an excellent tool for flow cytometers equiped with a 405 nm violet laser source. This DNA-binding dye might be used for multicolor analysis of live cells with the filter sets of Pacific Blue™ and BD Horizon™ V450.
Labeling the Nuclei of Dead Cells
Binding activity of Apopxin™ Deep Red to phosphatidylserine in Jurkat cells. The fluorescence images demonstrated that live cells (blue) were stained by CytoCalcein™ Violet 450, apoptotic cells (red) were stained by Apopxin™ Deep Red, and necrotic cells (green) were stained by Nuclear Green™ DCS1. Apoptosis was induced by 1 µM staurosporine for 3 hours. The fluorescence images of the cells were taken with Olympus fluorescence microscope using the violet, Cy5® and FITC channel respectively. A: Non-induced control cells; B: Triple staining of staurosporine-induced cells.
Nuclear Green™ DCS1, Nuclear Orange™ DCS1 and Nuclear Red™ DCS1 are fluorogenic, DNA-selective and cell-impermeant dyes for analyzing DNA content in dead, fixed or apoptotic cells. As the LCS1 reagents, the fluorescence of the DCS1 dyes is significantly enhanced upon binding to DNA. They can be used in fluorescence imaging, microplate and flow cytometry applications. These DNA-binding dyes might be used for multicolor analysis of dead, fixed or apoptotic cells with proper filter sets.
The normalized emission spectral comparison of Nuclear Green™ DCS1 (Ex/Em = 503/526 nm), Nuclear Orange™ DCS1 (Ex/Em = 514/555 nm), and Nuclear Red™ DCS1 (Ex/Em = 622/645 nm) in the presence of calf thymus DNA. The dotted line is emission spectrum of propidium iodide bound to DNA (Ex/Em = 535/617 nm).
Table 1. Cell Nuclear Stains.