On Thu, 14 Jan 1999, Mick Rentsch wrote:

> Try using sat. Aq. Alcian Green, Yellow or Blue (Usually about 4-5%)

 The permanence of alcian blue can be ensured by exposure to alkali
 (e.g. ammonia fumes). This causes hydrolysis of the dye, removing the
 cationic side chain that conferred both the positive charge and the
 solubility in water. In the case of alcian blue, the residual coloured
 compound is copper phthalocyanine, which is insoluble in everything
 (or should I have said anything?). For alcian yellow an insoluble
 azo dye should remain. Alcian green is a mixture of alcians blue and
 yellow.  Ref: Conn's Biological Stains, ed. RD Lillie, 9th ed. 1977.

 For black writing on ground glass, you can't beat an ordinary
 graphite pencil, followed by transparent nail varnish to protect
 against rubbing off. On smooth glass, a diamond pencil is
 permanent, but it's too troublesome for large numbers of slides,
 and flying ground glass granules can end up under the coverslip.

 John Kiernan
 London, Canada.