On Wed, 16 Dec 1998 RSRICHMOND@aol.com wrote:

> >>Supravital staining means putting a small drop of blood on a stained slide
> and adding a coverslip, then waiting for a few minutes for the living white
> cells to take up the stain. ... I use slides dipped in 0.25-0.5% toluidine
> blue (in absolute ethanol) and then dried on end at 60 degrees C.<<
>
> In the early 1960's when I was a medical student at Washington University in
> St. Louis (now the home of the Coenorhabditis elegans genome!) the
> hematologists, under the direction of the formidable Virginia Minnich, used a
> supravital stain for peripheral blood, using neutral red and malachite green
> and apochromatic lenses and a fair amount of mystery and mumbo-jumbo. Their
> differential counts always differed from the Wright-Giemsa results, and of
> course (by definition) were always right. I've never heard of this technique
> again, and I have no idea of its details.

   There is a similar method in which janus green (a blue dye) is
   deposited on the slide in readiness for a freshly smeared
   drop of suspended cells. It enters the mitochondria. This type
   of supravital mitochondrial staining has also been used to
   stain the presynaptic terminals of motor end plates in skeletal
   muscle - originally with janus green but in recent years with
   fluorescent styryl cyanine dyes.

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1
   Phone: (519) 679-2111
   FAX (Department): (519) 661-3936
   E-mail: kiernan@uwo.ca