A solution of 75% ethyl alcohol (ETOH) and alizarin red S can be substituted for
KOH-alizarin red S to stain bone. ETOH-alizarin, unlike KOH-alizarin, does not
damage muscle or cartilage. ETOH-alizarin and acidified alcian blue (a cartilage
stain) can be used in any order and as often as required to stain bone and cartilage
in a single preparation that has not been exposed to KOH-alizarin or trypsin, remembering
that the acidic effects of the alcian blue solution should be neutralized
to prevent decalcification of weakly ossified elements.