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Oxazole Yellow, 1 mM in DMSO

Oxazole yellow, also know as YO-PRO-1, is a green-fluorescent, cell-impermeant nucleic acid stain with excitation/emission maxima of 491/509 nm when bound to nucleic acids. Oxazole yellow can be used as a early marker of apoptosis.

Product Attributes

Cellular localization

Nucleus & cytoplasm

Assay type/options

No-wash staining, Real-time imaging

Cell permeability

Membrane impermeant




491/509 nm (with DNA)

Catalog #
1 mL
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Product Description

Oxazole yellow, also know as YO-PRO-1, is a green-fluorescent, cell-impermeant, high-affinity carbocyanine monomeric nucleic acid stain that is essentially nonfluorescent in the absence of nucleic acids but exhibits excitation/emission maxima 491/509 nm when bound to nucleic acids. Oxazole yellow is also used to identify apoptotic cells. Early apoptotic cells become permeant to oxazole yellow, but remain impermeant to propidium iodide (40016), a dead cell stain.

  • Monomeric nucleic acid stain
  • Cell-impermeant
  • Early marker of apoptosis
  • λExEm (with DNA) = 491/509 nm
  • Supplied at 1 mM in DMSO


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