TUNEL AND DAPI

[voland]

I am staining rat tissue with TUNEL and DAPI and many cells that are TUNEL positive dont stain with DAPI. How do you interpret this.

[excalibur]

The cells are picking up the TUNEL and the DAPI has no where in that cell to connect?

[voland]

That's a possibility but is this a known effect/fact. Most of the reports show nice pictures with TUNEL-DAPI doucle staining.

[richard03]

DAPI is not specific apoptosis marker. It just stains nuclei of cells and you identify the apoptotic cells based on its morphology. In later stage of apoptosis, all nuclei break apart and DAPI may not be able to stain them anymore. So TUNEL should be more reliable marker for apoptosis.

[wormlover]

Voland,

I am having the same problem with my TUNEL/DAPI staining in worm tissues.  Did you ever figure out an explanation?  Is it just that the cells are in the later stages of apoptosis and the DNA is too degraded?  I just wanted to confirm that my TUNEL positives are actually nuclei....

sarah

[voland]

Hi Sarah,

I dont know what the problem is. Maye your explanation is good but according to some apoptosis experts it should not be like that, DAPI should stain.