On Thu, 20 Apr 2000, Anna Logvinova wrote:

> I am looking for the best IHC or special stains for cellular membranes for
> light microscopy. Any help will be greatly appreciated!

  If you mean the surface membranes of cells, you can stain for
  any common component of the glycocalyx. A regular periodic
  acid-Schiff method should do nicely. Be careful not to
  overdo any counterstaining. The sensitivity is increased
  by examining with a fluorescence microscope: red fluorescence
  with a brownish cast to it. For stronger fluorescence you
  can use one of several alternatives to Schiff's reagent; my
  favourite is acriflavine-SO2, which gives exceedingly bright
  yellow fluorescence.

  The cell membrane of electron microscopy is, of course, far too
  thin to be resolved by light microscopy, but histochemical stains 
  for phospholipids demonstrate membrane-rich objects such as
  mitochondria and myelin sheaths. Baker's acid-haematein does a
  good job (blue) and so does sudan black B (black to grey). These
  methods require either frozen sections or adequately formaldehyde-
  fixed blocks that have been chromated to insolubilize the 
  phospholipids before dehydrating and embedding.

  There also exist various traditional staining methods for cell
  boundaries, either in confluent sheets such as hautchen preparations
  of endothelium or in sections of cellular tissues such as epidermis,
  kidney, liver etc. These methods probably deposit visible material
  in glycocalyx material and in the cracks between adjacent cells.
  I don't think these methods are much used these days (? famous last
  words). I have tried a couple of them and wasn't impressed, but
  didn't persevere. 0.5 to 1 um sections of glutaraldehyde-fixed,
  postosmicated and resin-embedded specimens show the cell boundaries
  and everything else pretty well when stained with an alkaline solution
  of a basic dye. The tissue preservation and optical resolution are
  probably the best that are possible with light microscopy, but the
  specimens have to be pretty small.

  Hope this helps a bit. If you give more details about your preparations
  and what you hope to see, you'll get lots of more relevant replies.

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1
   E-mail: kiernan@uwo.ca