Jennifer:

We acid wash slides before coating with poly-L-lysine.  For this procedure
we use 1% HCl in 70% ethanol for 5 minutes and triple rinse in distilled
water.

We acid wash glassware used for making and storing silver stains, and the
coplin jars used in silver staining procedures, BEFORE using them.  We use
potassium dichromate-sulfuric acid solution for this purpose.  Dissolve 200
g of potassium dichromate in 1 L of distilled water in a heatproof
container.  Slowly add 750 ml of concentrated sulfuric acid with stirring.
CAUTION:  THIS IS SERIOUSLY NASTY CORROSIVE STUFF.  THE REACTION IS
EXOTHERMIC.  Work in the hood with gloves, lab coat and eye protection.  The
solution can be reused until it turns green instead of orange-brown.  Expose
glassware to the acid bath for 30 minutes to 1 hour, decant, and triple
rinse in distilled water.  We use a huge Nalgene autoclave bin to contain
the bath.  Make sure to eliminate all traces of the acid wash from both the
interior and exterior of the glassware.  Dry inverted on lint-free towels
and store covered with parafilm.  Reference:  Sheehan, 2nd ed., p.134.

This sounds frightening on paper, but isn't bad in practice.

Hope this helps.
Regards -
Carol
*****************
Carol B. McCollough, HT(ASCP)
Diagnostics & Histology Laboratory Manager
Maryland Department of Natural Resources
Fisheries Service
Cooperative Oxford Laboratory
904 S. Morris Street
Oxford, MD 21654

-----Original Message-----
From: MacDonald, Jennifer [mailto:jmacdonald@sach.org]
Sent: Wednesday, August 11, 1999 11:38 AM
To: 'histonet@pathology.swmed.edu'
Subject: acid washed glassware


Is anyone out there acid washing their glassware?  If so what type of acid
are you using?  Do you acid wash all glassware or just after certain
staining procedures (ie silver stains)?

On another note:  I would be interested in any feedback on the BioGenex
Optimas Plus (reliability, quality of stains, service problems etc).


Jennifer MacDonald
San Antonio Community Hospital
Upland, CA  (909)985-2811 ext.4148
jmacdonald@sach.org