-----Original Message----- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of histonet-requ...@lists.utsouthwestern.edu Sent: Sunday, April 18, 2010 12:04 PM To: histonet@lists.utsouthwestern.edu Subject: Histonet Digest, Vol 77, Issue 22
Send Histonet mailing list submissions to histonet@lists.utsouthwestern.edu To subscribe or unsubscribe via the World Wide Web, visit http://lists.utsouthwestern.edu/mailman/listinfo/histonet or, via email, send a message with subject or body 'help' to histonet-requ...@lists.utsouthwestern.edu You can reach the person managing the list at histonet-ow...@lists.utsouthwestern.edu When replying, please edit your Subject line so it is more specific than "Re: Contents of Histonet digest..." Today's Topics: 1. Re: hematoxylin-eosin saffron (Robert Richmond) 2. Phospho antibodies and fixation (Jean-Martin Lapointe) ---------------------------------------------------------------------- Message: 1 Date: Sat, 17 Apr 2010 13:27:21 -0400 From: Robert Richmond <rsrichm...@gmail.com> Subject: [Histonet] Re: hematoxylin-eosin saffron To: histonet@lists.utsouthwestern.edu Message-ID: <g2yabea52a61004171027g1bfd628ezbc527449dc92b...@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 The hematoxylin-phloxine-saffron (HPS) stain is a trichrome stain that came into use as a "general oversight" stain by surgical pathologists in the 1930's, notably at Columbia-Presbyterian Hospital in New York City. The Goldner-Foot trichrome stain was also used for this purpose, on the other side of Central Park at Cornell Medical Center, probably abandoned after Chandler Foot's retirement in 1948. I actually saw the HPS stain in use at Columbia-Presbyterian around 1966, in place of H & E. I understand that it is still in very limited use in a few laboratories today. Saffron (a natural product, the stigmas of the flowers of Crocus sativus) is extremely expensive - currently $66 for a quarter ounce (about 7 grams) at Penzeys.com. It's used histologically as an alcoholic extract (supposedly best done with a reflux condenser) and can actually be purchased in that form. You can find the HPS staining procedure in older books, such as the AFIP manual. As a working surgical pathologist, I find this ancient technique intriguing but totally impractical in today's world. It's stretching it to get a trichrome stain for your liver biopsies these days. Bob Richmond Samurai Pathologist Knoxville TN ------------------------------ Message: 2 Date: Sat, 17 Apr 2010 16:47:48 -0400 From: "Jean-Martin Lapointe" <jm.lapoi...@accellab.com> Subject: [Histonet] Phospho antibodies and fixation To: <histonet@lists.utsouthwestern.edu> Message-ID: <befd613bd39142499989f836556ddc83c43...@ace.accellab.lan> Content-Type: text/plain; charset="iso-8859-1" Hi Ashley, I did a little bit of work on this a few years back. My belief is that the main difficulty with IHC for phospho-epitopes is not formalin fixation per se, but rather the instability of the phosphorylation. I used to work with rodent tumor models, where we collected solid tumors (or other tissues) just after sacrifice, and fixed them by formalin immersion. We found that the periphery of the tissues fixed this way expressed various phospho-epitopes quite well, but not the center. My interpretation was that by the time formalin had penetrated to the deep regions of the tissue, the phosphorylation had gone away (as you know formalin penetrates solid tissues fairly slowly). We proceeded to test matched tissue samples, fixed either in formalin at room temperature vs. cold formalin (formalin was at 4C at immersion, and the tissue was put in the fridge after sampling). We found that the cold formalin samples expressed phosphorylation sites fairly evenly, compared to only peripheral with the room temp samples. Presumably the cold temperature preserves the phosphorylation sites long enough to leave time for formalin to penetrate throughout. Consequently we integrated cold formalin fixation to all our IHC protocols for phospho-epitopes. Hope this helps, Jean-Martin Lapointe Accellab -----Original Message----- Good day colleagues, Does anyone have any information on phospho antibodies and fixation? Is there any reason to NOT fix specimens in formalin vs say, 70% EtOH? (and then process them through formalin later?) I can't seem to find any information on whether or not fixation in formalin does something strange to a phosphorylated protien and makes it a less accessible antigen. Also, on that same note, does retreival do anything to it? I am assuming that these antibodies go through the same testing for cross reactivity, etc (depending on the vendor) and are reliable when used properly (like any other antibody). I don't, however, know if there is enough of a difference in the epitope (the fact that it is phosphorylated) that would make it more susceptible to some strange cross linking with formalin (especiallly with phosphate buffered formalin). Any help with this topic would be greatly appreciated as I am uneducated in this area. Thanks, Ashley Troutman BS, HT(ASCP) QIHC Vanderbilt University Histopathology 1301 Medical Center Drive TVC 4532 Nashville, TN 37232 615-343-9134 _______________________________________________ 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 End of Histonet Digest, Vol 77, Issue 21 **************************************** ------------------------------ _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet End of Histonet Digest, Vol 77, Issue 22 **************************************** ******************************************************************************** This e-mail is intended only for the use of the individual or entity to which it is addressed and may contain information that is privileged and confidential. If the reader of this e-mail message is not the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is prohibited. If you have received this e-mail in error, please notify the sender and destroy all copies of the transmittal. Thank you University of Chicago Medical Center ******************************************************************************** _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet