Hi Jennifer, I always submerge my cassettes in molten paraffin until I embed them, so that isn't the problem. The histogel comes out of the processor hardened and whitish in appearance. I also melted the histogel tubes in hot water while preembedding the embryos, so that probably isn't the problem, either.
Jo Dee ~~Jo Dee Fish~~ Senior Research Technologist The J. David Gladstone Institutes Co-manager Histology and Microscopy Core Telephone: (415) 734-2567 Fax: (415) 355-0824 E-mail: <mailto:jf...@gladstone.ucsf.edu> jf...@gladstone.ucsf.edu Mailing address: The J. David Gladstone Institutes 1650 Owens Street San Francisco, CA 94158 _____ From: Hofecker, Jennifer L [mailto:jennifer.l.hofec...@vanderbilt.edu] Sent: Tuesday, February 03, 2009 10:37 AM To: jf...@gladstone.ucsf.edu; pam plumlee; histonet@lists.utsouthwestern.edu Subject: RE: [Histonet] Histo gel Issues Hi, Do either of you "dry embed" your Histogel blocks? By this I mean: Are you submerging the blocks in molten paraffin prior to embedding? Are they coming off the processor looking different, or are you finding it after you embed the gel blocks? Does it seem that the gel square is hard and never becomes one with the paraffin? If its after embedding, it may be dry embedding related. I use Histogel on a daily basis for clinical neurosurgery specimens and have had no trouble. I do submerge my blocks in molten paraffin after processing (holding tank of embedding center). I know several people who do not submerge and they had issues with the gel seeming hard and brittle. If you dry embed, you can get some good ones, but the likelihood of dried out "squares" is tremendous. Another suggestion may be the temperature of your Histogel. We once had an overzealous person heat the Histogel so hot that it was smoking (not the nice happy 50ºC that were used to). The block he made before I caught him was hard and brittle the next day while the others were not. I could notice this difference immediately upon taking them off the processor. I must also say that I have not purchased Histogel lately since I buy in large batches. If theres been a formula change or a lot related problem, it would not be affecting me yet. Good Luck and please let me know if I can be of any further assistance. Have a great week! Jennifer Jennifer L. Hofecker HT(ASCP) Vanderbilt University Medical Center Division of Neuropathology Nashville, TN ph 615.343.0083 fax 615.343.7089 -----Original Message----- From: Jo Dee Fish [mailto:jf...@gladstone.ucsf.edu] Sent: Tuesday, February 03, 2009 10:50 AM To: 'pam plumlee'; histonet@lists.utsouthwestern.edu Subject: RE: [Histonet] Histo gel Issues Dear Pam, I've had the same problem. I called Richard-Allen just after they were "absorbed" by Thermo Fisher and got no answers. They had never heard of such a problem and didn't know how to solve it. I have heard from another user that had the same exact problem. I lost precious samples, E6.5 mouse embryos, because of this "drying out and hardening" of the histogel. I had to stop using it all together. If anyone has any suggestions, please let us know! Take care Pam and all histonetters, Jo Dee ~~Jo Dee Fish~~ Senior Research Technologist The J. David Gladstone Institutes Co-manager Histology and Microscopy Core Telephone: (415) 734-2567 Fax: (415) 355-0824 E-mail: jf...@gladstone.ucsf.edu Mailing address: The J. David Gladstone Institutes 1650 Owens Street San Francisco, CA 94158 -----Original Message----- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of pam plumlee Sent: Monday, February 02, 2009 1:06 PM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] Histo gel Issues Dear Group: I'm having problems with the processing of small tissues in histogel. I follow the suggested embedding directions on the package and then process the gel blocks. The results are very inconsistent-ideally, I'll get nice soft gel blocks-but, usually in a batch of 10 I get 2 good blocks and 8 dried up, flat hard squares. They are all handled and processed the same. Anyone experience this before? Thanks for any input. Pam Plumlee H.T. Pfizer La Jolla pam.plum...@pfizer.com _______________________________________________ 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