DAPI is a popular nuclear and chromosome counterstain, showing a distinct banding pattern in chromosomes. DAPI emits blue fluorescence upon binding to the minor groove of dsDNA with a ~20-fold fluorescence enhancement. DAPI is provided as a 5 mg solid (C001) and a 5 mg/mL aqueous solution (C002).
| Specifications: | |
| Excitation/Emission: | 358/461 nm |
| Shipping Condition: | Ambient |
| Storage Conditions: | 2-8ºC, protect from light |
| Molecular Formula: | C16H17Cl2N5 |
| Molecular Weight: | 350.25 |
| CAS Number: | 28718-90-3 |
| Protocol (PDF): | C001 | C002 |
| MSDS (PDF): | MSDS-C001 | MSDS-C002 |
| COA (PDF): | COA-C001 | COA-C002 |
Reference:
J Biomol Screen (2004) 9:216-222
J Histochem Cytochem (2002) 50:877-884
J Biol Chem (2009) 284:13843-13855
Frequently Asked Questions (FAQs)
Is DAPI a good live-cell nuclear label?
DAPI is considered a semi-permeant/impermeant nucleic acid stain. Staining of nucleic is dependent upon the cell line in its performance. Some cell lines will label with DAPI, others not at all, and others label non-uniformly. Instead, we recommend using either Hoechst 33342 or Hoechst 33258, which have the same wavelength and binding mode as DAPI (at the A-T minor groove) but are readily cell-permeant.
My DAPI labeled samples have a strong blue background signal immediately after mounting. What can I do to fix this?
Some mounting medias can have strong blue autofluorescence. If you are seeing a high blue background, it could be coming from the mountant. Try labeling the sample and view it before (using a wet mount in buffer) and after mounting to determine if the background signal is coming from the mounting media or the sample itself.
