Rachel --
 
         3-4nm gold particles can be imaged (by reflection) very well after
silver intensification.  I've done it in cultured cells  -- I'm not sure
what would happen with sections of plastic embedded tissue, you may get
reflection throughout the specimen.  If you want to try it, I would
highly recomend  the silver-intensification method of Burry
(Immunogold-Silver Staining:  Principles, Methods, and Applications.
1995.  M.A. Hayat, Ed.  CRC Press.  pp. 217-230.)
 
                                                Good Luck!
 
TO THE REST OF THE LIST:  Does anybody know how small of a gold particle
can be imaged without silver intensification?
 
                                        Greg Martin
                                        Dept. of Cell Biology and Anatomy
                                        Johns Hopkins School of Medicine
 
On Tue, 26 Mar 1996, Rachel Teitelbaum wrote:
 
>     I am looking for anyone with experience utilizing 5nm gold particles,
> (or preferably smaller) for confocal microscopy.  I am hoping to use
> lowicryl embedded immunogold lablled material and optically section the
> blocks with the confocal.  Has anyone done this, or have a good reference?
>
>
>      Thanks!
>
> -Rachel
>