That would be called Nuclear Fast Red (Kernechtrot) Solution as listed in
Carson's Histotechnology:  A Self-Instructional Text.  It's made as
follows:

Nuclear-fast red . . . . 0.5 gm       (purchase from Sigma cat #N8002)
Aluminum Sulfate . . . 25.0 gm.
Distilled Water . . . 500.0 ml.

Dissolve the aluminum sulfate in the distilled water, then dissolve the
nuclear-fast red in this solution using heat.  Cool, filter, and add a few
grains of thymol as a preservative.


>Date: Fri, 05 Feb 1999 05:00:56 +0200
>From: vandeplas@aurion.nl (Peter van de Plas)
>Subject: C.I. 60760 "kernechtrot"
>To: Histonet@Pathology.swmed.edu
>
>Dear all,
>
>Could one of you give me the englisch/american name for the nuclear stain
>"kernechtrot" (german) or "kernechtrood" as we write in The Netherlands. We
>use this counterstain instead of heamatoxylin in our wet-workshops for
>those sections that contain low amounts of antigen. I only have a german
>written cataloque of Merck (were I purchased the product a long time ago)
>The C.I. number of  kernechtrot is 60760. The Merck cataloque number:
>15939.
>
>Thanks for your reply.
>Peter
>
>
>========================================
>Peter van de Plas
>AURION
>Costerweg 5
>6702 AA Wageningen
>The Netherlands
>phone: (31)-317-497676
>fax: (31)-317-415955
>http://www.aurion.nl
>