Just FYI, I have found the name to the benzothiazole dye noted above. It is: 5-chloro-2-[5-choro-3-(4-sulfobutyl)-2(3H)-benzothiazolidene)-2-metyl-1 propenyl]-3-(4-sulfobutyl)-benzothizolium hydrixide, inner salt, sodium salt CAS # 30457-67-1

Have fun with that one!

PE