Phil Bergin at Göteborg University in Sweden asks:

>>But is there a reason that people have stopped making Alcian Yellow? It’s a 
topic that seems to come up fairly often, and I was wondering why people have 
stopped making it if its in such high demand.<<

A lot of information about Alcian yellow and Alcian blue has been exchanged 
on this list. Briefly, the manufacture of these two dyes by the methods 
originally used to make them had to be stopped, because some unnamed 
carcinogenic synthetic intermediates could not be handled.

Dick Dapson at Anatech (a regular on Histonet, of course) worked out 
alternative syntheses that did not involve these intermediates. Currently 
Anatech is offering Alcian blue, and has announced the availability of Alcian 
yellow in the near future. (Note: I have no connection with Anatech.)

>From time to time Minggeng Wang, Ph.D at the Suzhou Sinoera Chem Co., Ltd. in 
China (the traditional English spelling of this place is Soochow) has 
announced the availability of both dyes, most recently in a communication 
yesterday. They stated that 

>>Both stains are produced by safe way and environment approval, they are not
started from the sym-dichlorodimethyl ether.<<
This is the first time I have seen the carcinogenic synthetic intermediate 
named. Is this in fact the intermediate that made the manufacturing process 
impractical?

Dr. Wang goes on to state:
>>Good news, we are just approved by BSC a bulk lot of Alcian Blue 8GX, lot 
20020129A early this month with the help of Mr. Frank Matthew of BSC. Our 
Alcian Blue 8GX is also being accepted/purchased by Merck KGaA, bulk lot.<<

Supposing that BSC is the Biological Stain Commission: can anyone on Histonet 
verify this? Did the BSC address the issue of environmentally appropriate 
manufacture when they issued this approval? If they didn't, should they have?

Bob Richmond
Samurai Pathologist
Knoxville, Tennessee USA