Oxazole yellow is a fluorescent cyanine dye that binds to DNA and is used to detect apoptotic cells. Oxazole yellow does not enter live cells. However, during apoptosis the cytoplasmic membrane becomes slightly permeable, allowing entry of the dye. Oxazole yellow is often used along with propidium iodide (catalog no. P4170), a DNA dead cell stain that does not enter either live or apoptotic cells. The λEx/λEm of Oxazole yellow is 491/509.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.