I must firstly qualify the following by stating that I have no personal
experience but maybe there are some histonetters, particularly those in
Europe, who do.

HJ Conn's Biological Stains Commission publication states that "'Astra Blue'
had been considered generally as a copper phthalocyanin and used in Europe
for the same purpose as alcian blue". Ole Wiebkin in Woods and Ellis,
'Mucosubstnces and macromolecular carbohydrates', states that "Alec blue
(also known as quaternized astra blue 6GLL) reacts with chondroitin sulphate
and is a suitable alternative to alcian blue".
Regards
Roy Ellis
roy.ellis@imvs.sa.gov.au