Using "pure" formaldehyde as a fixative is not a good idea (you already know that) and the staining will be affected BUT, on the other hand, IHC will only require stronger HIER (more time and temperature) but other than that I do think the epitopes will be detected. So the "effects" will be mostly "cosmetic".René J.
On Wednesday, October 22, 2014 11:04 AM, Orla M Gallagher <o.m.gallag...@sheffield.ac.uk> wrote: Dear Histonetters, What would the effect be of fixing tissues samples in concentrated formaldehyde instead of 10% buffered formalin? One of our researchers would like us to prepare some bones for histology staining which have been fixed in 37% formaldehyde by mistake and stored for 4 years. I assume there will be formalin pigment in these samples, so even a H&E may not look great, while any enzyme histochemistry or immunohistochemistry is probably not worth trying. I haven't seen the samples yet as they will be arriving from another UK university. Has anyone out there fixed any tissues in concentrated formaldehyde by accident or by design? Thanks, Orla -- ************************** Ms. Orla Gallagher Bone Analysis Laboratory Mellanby Centre for Bone Research Department of Human Metabolism D Floor Medical School University of Sheffield Beech Hill Road Sheffield S10 2RX UK Website: http://mellanbycentre.dept.shef.ac.uk Tel: 0044114-2713337 (office) 0044114-2713174 (lab) E-Mail: o.m.gallag...@sheffield.ac.uk *STOP*: Do you really need to print this e-mail? *BE GREEN:* Keep it on the screen. http://www.shef.ac.uk/faculty/medicine-dentistry-health/2.9274/emailwording http://www.sheffield.ac.uk/visitors/mapsandtravel _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet