We work with primary cells (fibroblast and mouse cells) and I never observed
the autofluorescence phenomena you described.  My best guess would be your
fixative...  We routinely use acetone, ethanol, methanol or a mix of
ethanol-methanol and it works just fine.

Marie-Hélène Rochon

"Dr. Sandra Masur" wrote:

> In primary fibroblasts cultured from mouse corneas, a minority of the cells
> have  cytoplasmic vesicles that fluoresce when excited by and viewed with
> FITC or Texas red filter sets on a Zeiss Axioskop. The cells are cultured
> in DMEM/F12 with 10% FBS to which ascorbic acid is added for 24 hrs prior
> to fixing.
>
> This fluorescence was found in cell fixed for 10 min with 3% p-formaldehyde
> and mounted in glycerol or PPD containing glycerol. These fixed cells have
> NEVER been exposed to antibodies conjugated with fluorochromes and yet
> these structures fluoresce very brightly.
>
> Has anyone else seen this in
> a) mouse cells? b) primary cultures?
>
> Any suggestions for how to quench this fluorescence?
>
> Do you have any suggestions
>
> Best regards,
> Sandra K. Masur, Ph.D.
> Box 1183
> Associate Professor
> Depts of Ophthalmology &
> Cell Biology/Anatomy
> Mount Sinai School of Medicine          phone: 212-241-0089 or 6544
> 1 Gustave Levy Place
> Annenberg Building 22-20
> New York NY 10029-6574                  fax: 212-289-5945
>
> e-mail: [log in to unmask]
>         [log in to unmask]