I agree with John on this, i think the " biggest single reason for this
improvement" could be disposable blades.
Patsy Ruegg

"J. A. Kiernan" wrote:

> RSRICHMOND@aol.com wrote:
> >
> > ups and downs, in general the slides are a great deal better than they were
> > when I was a resident. I have the abiding suspicion that improved embedding
> > media are the biggest single reason for this improvement.
>
> I wonder if this is really so. In the late 1970s Russ
> Allison did a comparative study of over 100 different waxes,
> additives etc:
>
>   Allison, RT. The crystalline nature of histology waxes: a
> preliminary communication. Med Lab Sci 35: 355-363.
>   Allison RT. The crystalline nature of histology waxes: the
> effects of microtomy on the micro-structure of paraffin
> wax sections. Med Lab Sci 1979; 36: 359-372.
>
> He found that they were all pretty much the same. I don't
> think the proprietary waxes like Tissuemat and Paraplast
> have changed since before the 1970s. Here we used to mix
> one of these with 2 volumes of Parowax, a cheap domestic
> paraffin sold in stores for making candles, putting on
> top of home-made jam etc. (Parowax alone was just a little
> too hard for easy sectioning, or so the experienced chief
> technician told me; I never tried it myself, but used the
> mixture a lot in those days.)
>
> -------------------------
> John A. Kiernan
> Department of Anatomy and Cell Biology
> The University of Western Ontario
> London,   Canada   N6A 5C1
>    kiernan@uwo.ca
>    http://publish.uwo.ca/~jkiernan/