On Thu, 5 Nov 1998, Pam Plumlee wrote:

> Histonetters:  Has anyone out there heard of or done a Lactate
> Dehydrogenase stain on formalin fixed or frozen human tissue?  My
> researcher has asked if I can do this stain to demonstrate thermal
> damage in skin.  Any leads would be greatly appreciated.
> pplumlee@thermolase.com

   Unlike most dehydrogenases, lactate dehydrogenase activity
   survives moderate formaldehyde fixation, so you don't have
   to work with unfixed cryostat sections. There are cytoplasmic
   and mitochondrial forms of the enzyme. Histochemical
   localization is done with a tetrazolium salt, and NAD+ as
   the coenzyme.

   Biochemists often assay the LDH that oozes out of bits
   of tissue, to get a measurement of cellular damage following
   various experiments. If a cell has been wrecked, the
   enzyme leaks out into the extracellular fluid. I don't know
   if this could be seen histochemically or not.

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