Have you ever thought of doing a shrinkage test? Take a tissue specimen, and xerox or use a flat bed scanner. Put fixed sample between plastic sheets, and scan it as unfixed tissue, fixed before processing and then after processing while in a faced paraffin block. Take all the measurements and then do the calculations./ We used to xerox large stained bone sections, a clever way of getting a precise macro-images of a huge specimen to show gross features of a defect. This did a better job than trying to do a macro-photo with a camera or through a microscope (the latter doesn't happen).
Years ago, when preparing for HTL exam practical, the samples e.g. tissue sections submitted had to be within a certain size range, and it was duly noted that after processing, the samples had shrinkage. This required going back to fixed tissue and cutting a bigger piece to compensate for the shrinkage and have a final correct sample/section size to follow the practical rules. As for GMA, there is a special processing schedule given to me that does not use alcohol dehydration (for lipid staining work). This protocol uses an GMA/watergradient since GMA is miscible with water. I would think there would be even less shrinkage with a water/GMA gradient and the source of shrinkage would come from the heat of polymerization and possibly a bit from kind of fixative used. The heat can controlled to some degree by doing polymerization on ice, or in a refrigerator, with the round JB4 metal chucks to dissipate the heat. Once again, I agree with Bryan Hewlett's assessment of shrinkage. Gayle Callis HTL/HT/MT(ASCP) Bozeman MT -----Original Message----- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Edwards, Richard E. Sent: Wednesday, August 25, 2010 7:50 AM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] shrinkage/a howlong is a piece of string type question Many thanks to all who responded, for paraffin processed tissues the figures suggested for the amount of shrinkage found or expected were :- "more than 5%":"5-10%":"10%"(twice):"10-15%":"20%":"25%":"30-35%":"30-40%", one responder felt it was "noticeable" and another thought it was a "fairy tale" concocted by pathologists............unsurprisingly many responders thought that the degree of shrinkage was dependent on the fixative used, processing schedule and the nature of the tissue itself, e.g. amount of lipid present. As far as shrinkage with GMA processed tissue go, a single response of "5%" was quoted. Richard Edwards _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet __________ Information from ESET Smart Security, version of virus signature database 5394 (20100824) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5394 (20100824) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5396 (20100825) __________ The message was checked by ESET Smart Security. http://www.eset.com __________ Information from ESET Smart Security, version of virus signature database 5396 (20100825) __________ The message was checked by ESET Smart Security. http://www.eset.com _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet