Why my bacteria cells look weird in DAPI fluorescence? - (Mar/28/2016 )

Hi all,

Are bacteria cells supposed to look smaller and not in their own shape when in fluorescence?

I did DAPI fluorescence stain to view my bacteria, I did not see any single bacillus like in the slide. I saw what supposed to be cell clump, but in it the cell that fluoresces looks so weird, it was like little spots. Overall, I just could not see bacillus shaped creatures. All I see was cell clumps (attached in pic here).

I did gram stain on my bacteria cells and confirm it is indeed bacillus. 

I use x40 on both. (maximum on the microscope)

Attached are the pictures.

Pls help.

When you stain with DAPI, only the nuclei will fluoresce, as DAPI associates with DNA. (https://en.wikipedia.org/wiki/DAPI). The cell body or outline will not be seen or will appear very faint compared to the much smaller nuclei which will fluoresce brightly.

keep in mind that meg p. anula is staining bacteria. no nucleus. however, the dna is stained, not the membrane or wall.