Description
Product Usage Information
Directions for Use: DAPI is supplied as a lyophilized powder. For a 20 mg/ml stock, reconstitute the 1 mg in 50 µl deionized water or dimethylformamide. Please follow CST's recommended IF and Flow protocols. For both applications, following secondary detection: Immunofluorescence: Counterstain with DAPI as the final step in your staining procedure. Rinse samples twice in PBS for five min each. Dilute DAPI stock solution to a concentration between 1 - 0.1 µg/ml in PBS and incubate for 5 min at room temperature in the dark. Rinse samples once in PBS and then prepare for imaging. Examine immediately using appropriate excitation wavelength. Alternatively, dilute DAPI stock solution to a concentration between 1 - 0.1 µg/ml in mounting media, apply to cells, and prepare for imaging. Examine immediately using appropriate excitation wavelength. Flow Cytometry: Rinse samples once in Incubation Buffer. Dilute DAPI stock solution to a concentration between 1.60-0.400 µg/ml in PBS and incubate for 15 min at room temperature in the dark before analyzing cells on flow cytometer.
Storage
Store lyophilized or in solution at 4°C, desiccated. Protect from light. In lyophilized form, the chemical is stable for 24 months. Once in solution, use within 2-3 weeks to prevent loss of potency. For long-term storage, aliquot and store at -20°C to avoid multiple freeze/thaw cycles.
Background
4', 6-diamidino-2-phenylindole, dihydrochloride (DAPI) is a blue fluorescent DNA dye that targets double-stranded AT clusters in the DNA minor groove (1). One molecule of dye binds to each 3 base pairs of dsDNA and yields an approximate 20-fold fluorescent enhancement (2). The level of DAPI-DNA fluorescence is proportional to DNA content (3).
Alternate Names
cellular dyes; DNA dye
