i would think u are correct in advising formic acid decal and then processing into paraffin for the best protection of the trap enzyme, immunoreactivity, etc. A couple of weeks in formalin should be fine. Paraformaldehyde show be the same as formalin. I do know a way to restore the enzyme activity for TRAP that may have been lost so if u need that let me know. --------- Original Message --------- Subject: AW: [Histonet] Bone samples long-term storage in 10% formalin or 4% paraformaldehyde From: "Gudrun Lang" <gu.l...@gmx.at> Date: 12/5/13 11:42 am To: "'Orla M Gallagher'" <o.m.gallag...@sheffield.ac.uk> Cc: histonet@lists.utsouthwestern.edu
Paraformaldehyd is formaldehyd in solid form. Formalin is the aequous solution of formaldehyd. So the main characteristics are the same. Gudrun Lang -----Ursprüngliche Nachricht----- Von: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] Im Auftrag von Orla M Gallagher Gesendet: Donnerstag, 05. Dezember 2013 19:31 An: histonet@lists.utsouthwestern.edu Betreff: [Histonet] Bone samples long-term storage in 10% formalin or 4% paraformaldehyde Dear Histonetters, What is your opinion on storing bone samples long-term (more than a couple of weeks) in 10% formalin? As I was taught, best practice has always been to fix only as long as necessary, depending on the size of the sample, then decalcify and process to wax, and I always stress this to everyone I advise. However, research colleagues sometimes wish to do histology on bone samples that have been stored for months ..or even years! As the formalin pH becomes more acidic, there is formalin pigment and the immunoreactivity and TRAP enzyme activity is diminished or destroyed during long fixation, is there any way of minimising this e.g. has anyone tried regularly replacing the old formalin with fresh buffered formalin, or storing formalin-fixed bones in any other medium? I'm also interested in how best to fix in 4% paraformaldehyde and whether the problems are the same with long-term storage. Thanks for your comments. All the best, 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. *Times Higher Education University of the Year* Data protection and confidentiality: The information contained in this message or any appended documents may be privileged and confidential and is intended for the exclusive use of the addressee(s). If you are not the addressee, any disclosure, reproduction, distributions, other dissemination or use of this message is strictly prohibited and may be unlawful. If you receive this correspondence in error please contact the sender immediately and permanently delete/destroy what you have received. _______________________________________________ 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 _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet