[Histonet] Lactophenol Cotton Blue Stain

[taylor alan]

Dear All

I wonder if some of you could answer the following for my colleagues and
myself.

For many years we have traditionally used our own 'in house' prepared
Lactophenol Cotton Blue, with or without KOH as an initial screening tool.

The question I have is which strength of Lactic Acid are others using if
they still make their own formulation. We have always used 80% puriss grade.

Our formulation is.

Lactic Acid 80%  20ml
Phenol Crystals   20g
Glycerol              40ml
Distilled H2O       20ml
Aniline Blue         50mg

The Aniline Blue is dissolved in the distilled water in a 100ml conical
flask and placed on a non heated magnetic stirrer for 24 hours.

The following day this solution is filtered into another flask, placed in a
fume hood, then the lactic acid, phenol and glycerin are added, placed back
on the stirrer for a couple of hours before being placed in the stock bottle
for use.

I have looked through much of the historical reference material and more
recent references but nowhere it seems does anyone state the concentration
of Lactic Acid.

I would very much like to hear from others on their experiences of using
this simple preparation and any other concentrations of Lactic Acid they
have knowledge of.

Kind regards

Alan Taylor BSc(Hons) FRMS
Microtechnical Services
71 Sweetbrier Lane
Heavitree
Exeter. Devon. EX1 3AJ