Dear histonetters:

I have a question re use of methyl green counter staining.  An investigator
used two procedures, with different results:

1. after immunostaining, counterstained with methyl green dissolved in 1M
sodium citrate pH4.0, then washed in water, dipped in butanol, then xylene.
 The color was green.

2. after immunostaining, the counterstain solution was the same methyl
green solution as in #1, then washed with distilled water.  Color was
bluish.  Why the different color result? - Why is #2 blue, not green. Is
this because of the methyl violet in the stain and the acidic conditions?.

3. The texts recommmend 1% methyl green in distilled water - is this the
general recommendation out there?.  I presume chlorofrom extraction of MG
is not necessary for routine counterstain use, only for use in DNA,RNA
staining.



Dr Robert G. Russell
Director
Histotechnology and Comparative Pathology Facility
Forchheimer  734
Phone: (718) 430-3209
Fax:   (718) 430-3243
E-mail:  russell@aecom.yu.edu

mail address:
Ullmann Building, Room 1005,
Albert Einstein College of Medicine
Jack and Pearl Resnick Campus
1300 Morris Park Av., Bronx, NY, 10461.