Dear Confocalists, I am trying to determine the shapes of the cells grown in dense 3-D cultures by means of membrane staining dye DII. The problem is that I have to fix the cells before the observations. Both formaldehyde and glutaraldehyde that I used for fixation seem to destroy cell membranes so their fluorescence after staining is barely observable. I would greatly appreciate any sugestions concerning fixation protocols or solutions that would fix the cells not destroying the structure of their membranes. Thanks in advance, Jarek Czyz Dr. Jaroslaw Czyz Department of Cell Biology The Jan Zurzycki Institute of Molecular Biology al. Mickiewicza 3 31-120 Krakow Poland [log in to unmask]