NucTO-3 Iodide (642/660)

NucTO-3 Iodide (642/660) is a far-red to near-infrared fluorescent nucleic acid stain designed for sensitive visualization of DNA and RNA in fluorescence-based workflows. As an iodide salt, it is typically used as a membrane-permeable or nucleic-acid-associated dye for labeling nucleic acids in fixed or permeabilized samples, with excitation and emission positioned in the 642/660 nm window that aligns well with common red/Far-red laser and filter sets used in fluorescence microscopy and cytometry. Its strong fluorescence when bound to nucleic acids makes it a practical reagent for nucleic acid quantification and imaging in molecular biology and cell biology assays.

1. Nucleic Acid Staining Assays

NucTO-3 Iodide (642/660) is used to stain DNA and RNA for fluorescence readouts in nucleic acid analysis workflows, including gel-free quantification formats and plate-based staining assays. Researchers often incorporate the dye into staining protocols to visualize nucleic acid content in purified samples, nucleic-acid standards, and experimental extracts, taking advantage of the far-red emission to reduce interference from common green autofluorescence. In assay development settings, the dye's 642/660 spectral positioning supports multiplex-friendly experimental designs where green channels are reserved for other labels.

2. Fluorescence Microscopy Imaging

NucTO-3 Iodide (642/660) supports fluorescence microscopy studies where nucleic acids must be visualized in fixed cells, permeabilized specimens, or prepared nucleic-acid samples. Cell biology groups use the stain to generate clear nuclear and total nucleic-acid signal for imaging-based quantification, including comparative studies of nucleic-acid distribution across experimental conditions. The far-red excitation/emission window also helps improve background performance in thick or autofluorescent samples, making it a useful stain for routine imaging on fluorescence microscopes equipped with red or far-red filter sets.

3. Flow Cytometry DNA Content Analysis

NucTO-3 Iodide (642/660) is commonly applied as a DNA/RNA fluorescent stain for flow cytometry workflows that require nucleic-acid-dependent fluorescence readouts. Cytometry users rely on the dye's far-red spectral profile to measure nucleic-acid content in stained cell populations, supporting gating strategies and population comparisons in cell-cycle and nucleic-acid profiling experiments. The 642/660 nm compatibility is particularly useful when red channels are already allocated for other fluorophores, enabling nucleic-acid staining without forcing additional spectral overlap into the green region.

4. Multiplex Fluorescent Labeling Workflows

NucTO-3 Iodide (642/660) is integrated into multiplex fluorescence experiments where nucleic acids are labeled alongside other biomolecular stains or reporter dyes. Researchers frequently pair the far-red nucleic-acid signal with green or orange fluorophores to separate channels cleanly and maintain robust visualization of both nucleic-acid structures and additional targets. In imaging and assay development, the dye's spectral placement helps streamline panel design for experiments that require nucleic-acid context while preserving optical separation among multiple fluorescent labels.