Bobbi,


     Autofluorescence can be brought on by certain endogeous tissue
     constituents, ie. fibronectin, lipofuscin and elastin, as well as by
     fixation in aldehydes.

     You don't say if your sections are fixed or not. If so, you should look at
     using sodium borohydride (0.5mg/ml in PBS) for 5 minutes (glutaraldehyde)
     or PBS plus a few drops of 1M glycine(formaldehyde) to block any reactive
     groups. ***sodium borohydride is flammable on contact with water, and
     harmful by ingestion, inhalation etc.Take adequate precautions***

     Another thing to consider is reducing the section thickness, if possible,
     as the intensity of autofluorescence is related to this.

     You also don't mention what fluorochromes you are using. It may be
     worthwhile trying a fluorochrome of a longer wavelength as there is less
     likelihood of any spectral overlap with the endogenous material. As I
     mentioned in an earlier posting today. we have had good results switching
     to the Alexa dyes (Molecular Probes).

     Good luck

     Ronnie Houston
     Regional Histology Operations Manager
     Bon Secours Helath Partners Laboratories
     5801 Bremo Road
     Richmond, VA 23226


______________________________ Reply Separator _________________________________
Subject: Autofluorescence
Author:  "Miller, Barbara"  at BSHSIBTW
Date:    4/12/02 11:58 AM








       I am having trouble with autofluorescence in frozen liver
       sections.  Does
       anyone have a way to minimize or remove this type of
       fluorescence?  Any
       advice in re this would be appreciated.

       Thank you,

       Bobbi Miller
       Dept. of Gastroenterology
       Roudebush VA Medical Center
       Indianapolis, IN

       e-mail    bmiller2@iupui.edu