embryo transfer

[Robert Burns]

Hi,
   I am posting this on behalf of a friend who is involved in mouse
embryo transfer work. Does anybody know of non-toxic stain that can
be used to visualise pre-implantation embryos? At present he is 
getting fair low yields and is attributing this to not being able to
see the embryos properly.


Thanks

Robert
Robert Burns

Monoclonal Antibody Unit
Scottish Agricultural Science Agency
East Craigs
Edinburgh
Scotland

burns at sasa.gov.uk