weird green threads on my slide

[aana bock]

Hi all

I have been trying to image my GFP transfection slide-HEK293 CELLS are used for transfection. I used methanol:acetone (1:1), DAPI and Mowiol with in between PBST washes. My tranfection works decent but i get these weird green thread like structures which illuminate in DAPI filter but not in GFP filter on microscope. Has anyone see these before?? I am attaching document with image. 

thanks for the help!!

aana