Principle
The fluorescent dye DAPI binds selectively to DNA and forms strongly fluorescent DNA-DAPI complexes with high specificity. DAPI, once added to tissue culture cells, is rapidly taken up into cellular DNA, yielding highly fluorescent nuclei and no detectable cytoplasmic fluorescence. When the cells are contaminated with Mycoplasmas, characteristic discrete fluorescent foci are readily detected over the cytoplasm and sometimes in intercellular spaces.
Preparation Note
Working solution: Solubility: 25 mg/ml in water
Preparation of stock solution
Dissolve in double-dist. water to a final concentration of 1 to 5 mg/ml.
Note: Do not use any buffers.
Preparation of working solution
Dilute the stock solution with methanol to a final concentration of 1 μg/ml. The working solution is stable at 2 to 8 °C for about 6 months.
Storage conditions (working solution): Stock solution (1 to 5 mg/ml) at -15 to -25 °C for 12 months.
Working solution (1μg/ml) at 2 to 8 °C for about 6 months.
Quality
Purity: >90% (from N)
Reconstitution
In 2 to 10 ml double-dist. water; 1 to 5 mg/ml final concentration.
Note: Prepare aliquots and store at -15 to -25 °C.
Application
DAPI is a fluorescent dye that binds selectively to double-stranded DNA and forms strongly fluorescent DNA-DAPI complexes with high specificity.
[1]
[2]
[3]
[4]
It is commonly used to detect mycoplasma in cell culture via fluorescence microscopy.
[5]
DAPI is several times more sensitive than ethidium bromide for staining DNA in agarose gels. It may be used for photofootprinting of DNA, to detect annealed probes in blotting applications by specifically visualizing the double-stranded complex, and to study the changes in DNA and analyze DNA content during apoptosis using flow cytometry. DAPI staining has also been shown to be a sensitive and specific detection method for mycoplasma.
温馨提示：不可用于临床治疗。