We have a GLP person who is not familiar with Histology at all. We have had to educate her about these issues and may other things. Calibration finally came down to having a PM on the units every year. After she understood all the things we do with a section during the cutting phase and pick up that would alter a true measurement.
We also do MMA sections on the microtome and even those are next to impossible to measure due to some stretching of the section during pick up and drying. Oh Yes, the drying of the slides really put her in a tail spin as this was just not allowing the sections to stay the same as when they were picked up. Sometimes a long talk and demonstration is the only way to make the point that we are not standardized like clinical chemistry etc. Pamela A Marcum University of Pennsylvania School of Veterinary Medicine Comparative Orthopedic Laboratory (CORL) 382 W Street Rd Kennett Square PA 19438 610-925-6278 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rene J Buesa Sent: Friday, October 31, 2008 10:08 AM To: Dr. med. Frauke Neff Cc: histonet@lists.utsouthwestern.edu Subject: Re: [Histonet] Microtome calibration Frauke: That calibration is ussually done by measuring the advance mechanism of the block holder and how many µm the block moves towards the blade, but that is rubbish. René J. --- On Fri, 10/31/08, Dr. med. Frauke Neff <[EMAIL PROTECTED]> wrote: From: Dr. med. Frauke Neff <[EMAIL PROTECTED]> Subject: Re: [Histonet] Microtome calibration To: [EMAIL PROTECTED] Cc: histonet@lists.utsouthwestern.edu, [EMAIL PROTECTED] Date: Friday, October 31, 2008, 9:41 AM Dear Dr. Girish, I agree with rene, if the qualitiy of the cuts is fine it doesn't matter if they are 1µm or 2.3µm thick. But I'm highly interested in how your GLP auditors want to calibrate the thickness of the section cuts. Are you supposed to measure the slides after cutting?! Before or after stretching in the water bath?! If they have a protocol how to do this I would be happy if they can share it with us. Frauke Quoting Rene J Buesa <[EMAIL PROTECTED]>: > Dr. Girish: > > BOTH "requirements" are rubbish invented by bureaucrats with lots of time in > their hands and trying to appear concerned and knowledgeable. > > Thickness is not necessary as long as the section is diagnostically useful or > if some quantitative method as to the intensity is done in which case > thickness = amount of matter, and would influence the outcome of the > quantitative process. > > Timing the tissue processor is also totally irrelevant because it does not > really matter a few minutes each way during a processing protocol. More > important would be to keep a record of the fixation time that is the only > step really critical in tissue processing. > > René J. > > --- On Fri, 10/31/08, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> > Subject: [Histonet] Microtome calibration > To: histonet@lists.utsouthwestern.edu > Date: Friday, October 31, 2008, 2:49 AM > > > > Dear all > > Is anyone practising microtome calibration for thickness of sections cut? > Our GLP auditors are frequently asking for it. > They also suggest that automatic tissue processor time in each reagent > should be calibrated. > > any comments > > Regards > Dr Girish > India > > > > > > _______________________________________________ > Histonet mailing list > Histonet@lists.utsouthwestern.edu > http://lists.utsouthwestern.edu/mailman/listinfo/histonet > > ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. _______________________________________________ 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