Several people have commented on marking prostate biopsy specimens for the 
embedder.

Speaking as the end user, I don't care what you mark it with, as long as you 
find all the pieces and tamp them flat in the paraffin!

I think that mercurochrome, though commonly used, is unacceptable because of 
its high mercury content (26%). I've seen people get by with ordinary eosin. 
Green Davidson marking ink looks horrible, but I've used it and it gets the 
job done, and is probably preferable when the embedder has to work without 
adequate light or magnification, or has impaired vision (all situations I see 
commonly in my travels).

The important thing is for the embedder to find all the pieces, each of which 
represents a moment of agony for the unfortunate patient. The person doing 
the grossing should be counting the cores and estimating their total length. 
("three strips of white tissue with an aggregate length of about 60 mm") It's 
not commonly done, but if I ran the zoo the person doing the grossing (or 
their assistant) would write these counts on a log sheet for the embedder.

Bob Richmond
Samurai Pathologist
Knoxville TN