[Histonet] Timm silver sulphide method for light microscopic localisation of heavy metals.

[Chris.Goodall <@t> bristol.ac.uk]

Dear All,
    I have been asked to try the Timm method on some FFPE samples of 
human brain. The papers I have read give methods for perfusing rat 
brain with sodium sulphide solution followed by 3% gluteraldehyde in 
0.15M phosphate buffer, and further treatment with sodium sulphide 
solution, or, post mortem brain samples snap frozen and frozen 
sectioned. However health and safety rules here do not permit frozen 
sectioning of unfixed human brain, or the use of gluteradehyde in the 
embalming room, so I am going to attempt this method on formalin fixed 
samples.My question is, has anyone experience of this method or any 
suggestions? It is mentioned that autopsy material left in situ for one 
or two days post mortem with no fixation may have enough endogenous 
sulphide ions or sulphide groups in the tissue due to autolytic 
activity and sulphide treatment may not be necessary, or if it is 
necessary, does anyone have experience of timing in the sulphide 
solution and is post fixation necessary after the initial formalin 
fixation. The paper also mentions that to prevent loss of 
metallosulphides present in the tissue the temperature of the wax 
should not exceed 50C which means the use of the dreaded low 
temperature wax, has anyone used conventional paraffin wax and got away 
with it?
Sorry for the long request,and thank you,
Chris Goodall