Nuclear counterstain for fluorescence microscopy
A popular nuclear and chromosome counterstain, DAPI (4′,6-diamidino-2-phenylindole) emits blue fluorescence upon binding to AT regions of DNA.
This protocol can be used for:
- Nucleic acid (nuclear) staining in fluorescence microscopy
This protocol should not be used for:
- Flow cytometry
|1. Add 2 mL of deionized water (diH2O) or dimethylformamide (DMF) to the entire contents of the DAPI vial to make a 14.3 mM (5 mg/mL) DAPI stock solution. Note: DAPI has poor solubility in water, so sonicate as necessary to dissolve. The 5 mg/mL DAPI stock solution may be stored at 2–6°C for up to 6 months or at ≤–20°C for longer periods.|
|2. Add 2.1 µL of the 14.3 mM DAPI stock solution to 100 µL PBS to make a 300 µM DAPI intermediate dilution|
|3. Dilute the 300 µM DAPI intermediate dilution 1:1,000 in PBS as needed to make a 300 nM DAPI stain solution.|
Labeling fixed cells
First, fix and permeabilize cultured cells with a protocol appropriate for your sample.
|1. Wash the cells 1–3 times in PBS as needed.|
|2. Add sufficient 300 nM DAPI stain solution to cover the cells.|
|3. Incubate for 1–5 minutes, protected from light.|
|4. Remove the stain solution.|
|5. Wash the cells 2–3 times in PBS.|
|6. Image the cells.|
|Standard filter set||DAPI|
|EVOS® Light Cube||DAPI|
- DAPI is a known mutagen and should be handled with care.
Drosophila melanogaster embryo staining. Wild type (Canton-S) Drosophila melanogaster embryo exhibiting microtubule staining (green fluorescence), denticle band staining (red fluorescence), and nuclear staining (blue-fluorescent DAPI).