On Thu, 28 Sep 2000, Dr Murray wrote:

> I am looking for calcium staining that can pick up
> calcium in the brain. If anyone has experinence in
> this are could you please send me protocols
> 
> I have found several methods in Thompson 1966
> "Selected histochem and histopath methods". However I
> am not sure if they have been used in the brain, to
> see low quantities of calcium in the brain regions.
> 
> These methods include:
> Von Kossa (modified Mallory)
> Alizarin Red (McGee Russell)
> Murexin (Kaufman and Adams)
> Napthochrome Green B stain (Denz, modified by Pearse)

  These methods will stain calcified deposits but are
  not sensitive enough to detect the much lower
  concentrations of calcium that can be precipitated
  from extracellular fluids by fixatives containing
  fluoride, oxalate or pyroantimonate ions. 

  The glyoxal-bis(2-hydroxyanil) method is much more
  sensitive, but it's easy to get false-positives from
  traces of calcium picked up from tap water etc. See
  Wolters,GHJ et al 1979 Histochemistry 62:137-151 and
  Harrison,JD et al 1993 Histochemistry 100: 155-159
  for applications and critical comment on the GBHA
  method. Vohringer,P et al 1995 have reviewed the
  precipitation of Ca by anions in fixatives for
  subsequent electron microscopy of CNS tissue.

  The sensitive calcium-indicating fluorochromes (FURA-2
  etc) show the minute amounts of free Ca present in
  living cytoplasm, but I've not heard of these being
  used as ordinary stains for fixed material.

  The choice of method depends on the nature of the
  calcium compound you need to demonstrate. 

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1