DAPI Nuclear Stain

DAPI is a widely used blue fluorescent dye that binds to DNA and serves as a nuclear counterstain in fluorescence microscopy, immunocytochemistry, chromosome staining, and flow cytometry. It binds to the minor groove of double-stranded DNA and exhibits a significant increase in fluorescence—about 20-fold—upon binding. Due to its potential toxicity in solid form, we offer DAPI as a convenient and safer, ready-to-use aqueous solution.

At standard staining concentrations (approximately 1 µg/mL), DAPI is not permeable to live cell membranes, making it ideal for staining nuclei in fixed cells or tissue samples. It is important to note that DAPI dyes can undergo UV-induced photoconversion, which may lead to additional fluorescence signals in the FITC or Cy®3 (green) channels. This effect can interfere with the imaging of other fluorescent probes or labeled antibodies. For this reason, we highly recommend imaging DAPI with the Atlas™ Imaging System, which is specifically designed to minimize crosstalk—reducing it to a level that is barely detectable.

Specifications 

DAPI Nuclear Stain PN 927-21974 contains 10 mg/mL in 1 mL H2O.

For Research Use Only. Not for use in diagnostic procedures.

Storage 

Store at 4 °C, protected from light. This product is stable for at least 1 year from date of receipt when stored as recommended.