Susanna-
We have had the same experience with cultured cells.  The solution is
to fix for 10 min, which we do at 37 degrees centigrade, and then to
rinse the cells exhaustively with PBS.  The cells seem equally well
fixed with this protocol, as if you left them in formaldehyde for a
longer time.  Don't know about tubulin.
Carol


>We are working with malaria parasites expressing GFP in their
>cytoplasm. Frustratingly, the GFP signal is greatly diminished if not
>abolished after paraformaldehyde fixation. Instead, we see a marked
>increase in autofluorescence. I wonder if others had similar
>experiences.
>
>Ute
>
>>Dear confocalist,
>>
>>I'm trying to make immunofluorescence of Tubulin in GFP transfected
>>cells. I have a good staining fixing with cold methanol but I loose the
>>GFP signal. With PF the tubulin staining is not so good. Any suggestion?
>>
>>Susanna
>--
><> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <>
>
>Ute Frevert, D.V.M., Ph.D.
>New York University School of Medicine
>Department of Medical and Molecular Parasitology
>341 E 25 St
>New York, NY 10010
>Tel:   212-263-6755
>FAX: 212-263-8116
>e-mail: [log in to unmask]