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Thiazole Red (TO-PRO®-3), 1 mM in DMSO

Thiazole red, also known as TO-PRO®-3, is a cell-impermeant, high-affinity far-red nucleic acid stain.

Product Attributes

Cellular localization

Nucleus & cytoplasm

Assay type/options

No-wash staining, Real-time imaging

Cell permeability

Membrane impermeant

Apoptosis/viability marker

Dead cell stain




642/661 nm (with DNA)

Note: Due to operating restrictions related to our COVID-19 response, primary antibody conjugates of R-PE, APC, PerCP, HRP, or AP are temporarily unavailable. All other antibody options are still available. We apologize for the inconvenience. Please see our easy-to-use Mix-n-Stain™ Antibody Labeling Kits for labeling antibodies with R-PE, APC, tandem dyes, and enzymes.
Catalog #
1 mL
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Product Description

Thiazole red, also known as TO-PRO®-3, is a cell-impermeant, high-affinity carbocyanine monomeric nucleic acid stain that is essentially nonfluorescent in the absence of nucleic acids but exhibits excitation/emission maxima ~642/661 nm when bound to nucleic acids. Thiazole red is also used as a nuclear counterstain and dead cell indicator.


TO-PRO is a registered trademark of Thermo Fisher Scientific.


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