We have processed and stained these types of samples before. We do not embed the pellets in agarose prior to processing. We dye them with eosin and place them in a tea bag and process on a very short cycle - 10 minutes per station, embed section and stain. We have stained with safranin O, alcian blue, toluidine blue and IHC for collagen II. The safranin O comes out just fine as well as the others. We just receive the samples so I do not know anything about the preparation, collection and fixation. It possibly could be your construct, we have processed hundreds of these samples and the staining intensity and patterns do change. I expect this is due to the type of preparation. If you want to see pictures of the staining, you can go to this website:
http://bioreagents.lifemapsc.com/products/purestem-chondropkg-4d20-8 or this paper: Sternberg H, Murai JT, Erickson IE, Funk WD, Das S, Wang Q, Snyder E, Chapman KB, Vangsness CT Jr, West MD. 2012 A human embryonic stem cell-derived clonal progenitor cell line with chondrogenic potential and markers of craniofacial mesenchyme. Regen Med. 7(4):481-501 Liz Elizabeth A. Chlipala, BS, HTL(ASCP)QIHC Premier Laboratory, LLC PO Box 18592 Boulder, CO 80308 (303) 682-3949 office (303) 881-0763 cell (303) 682-9060 fax l...@premierlab.com Ship to address: Premier Laboratory, LLC 1567 Skyway Drive, Unit E Longmont, CO 80504 ________________________________________ From: histonet-boun...@lists.utsouthwestern.edu [histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Victor Wong [vhlw...@yahoo.com] Sent: Monday, February 18, 2013 12:35 AM To: Tony Henwood (SCHN); histonet@lists.utsouthwestern.edu Subject: Re: [Histonet] Safranin O staining Dear Tony, Thank you for your prompt reply and the paper. I do fix the cell before processing in agarose and after embedding in agarose. It is inevitable to process in wax at higher than 45C as it is set by the routine workers. It is the first time I worked on cell block precessing. Do you have protocol of processing chondrogenic pellet by tissue processor? Any adjustment to my procesing and staining protocol? I tried to stain the pH1.0 alcian blue for 45 minutes and overnght but unremarkable staining (faint staining) was observed. Do you think glycosaminoglycans secreted by chondrogenic pellet can be destroyed by heat? Best Regards, Victor From: Tony Henwood (SCHN) <tony.henw...@health.nsw.gov.au> To: 'Victor Wong' <vhlw...@yahoo.com>; "histonet@lists.utsouthwestern.edu" <histonet@lists.utsouthwestern.edu> Sent: Monday, February 18, 2013 11:45 AM Subject: RE: [Histonet] Safranin O staining Victor, Heat can affect the way tissues and cells bind to dyes. I have attached an article that hints at some of these problems (Allison, R. T. and Bryant, D. (1998)'Effects of Processing at 45 C on Staining', Biotechnic and Histochemistry 73:3,128 -136). I have also found that some antigens are adversely affected by heat. CEA immunohistochemistry was decreased in cytology cell blocks made with molten agar compared to cell blocks made with fibrin clot. In both cases cell blocks were fixed in NBF after being made. Formalin seemed to protect the antigens in fibrin clots from subsequent heat damage during processing, whereas with agar cell blocks, the heat damage was already done. Regards Tony Henwood JP, MSc, BAppSc, GradDipSysAnalys, CT(ASC), FFSc(RCPA) Laboratory Manager & Senior Scientist Tel: 612 9845 3306 Fax: 612 9845 3318 the children's hospital at westmead Cnr Hawkesbury Road and Hainsworth Street, Westmead Locked Bag 4001, Westmead NSW 2145, AUSTRALIA -----Original Message----- From: histonet-boun...@lists.utsouthwestern.edu [mailto:histonet-boun...@lists.utsouthwestern.edu] On Behalf Of Victor Wong Sent: Monday, 18 February 2013 1:34 PM To: histonet@lists.utsouthwestern.edu Subject: [Histonet] Safranin O staining Hi all, I am working on induced chondrogenesis in cell culture. After, induction, I put the clump of cells (pellets) in 2% agarose to make a cell block. When the pellet did not sink to the bottom of agarose, I heated to melt the agarose again and centrifuged with higher speed. I fix the agar block in 10% formalin for an hour and then transfer to 70% alcohol and proceeded with normal paraffin procedure. I stained the paraffin sections with Sigma Safranin O stain but got very faint or no staining. Here is my protocol: 1. Weigert Iron Hx for 2 min 2. Acid alcohol,Scott Tap and wash 3. 0.02% fast green for 2 min 4. 0.1% acetic acid for 1 min 5. Sigma's Safranin O for 5-10 min 6. 95% alcohol then 3x 100% alcohol @3 min 7. xylene and mount I also tried to stain the sections with alcian blue pH1.0 and the staining was not quite remarkable. I'd like to ask if repeated heating on embedded pellet affects staining as I wanted to make sure the pellet was at the bottom of agarose. Are there other factors affect the staining. Any comments are welcomed. Thanks you in advance. Victor _______________________________________________ Histonet mailing list Histonet@lists.utsouthwestern.edu http://lists.utsouthwestern.edu/mailman/listinfo/histonet ********************************************************************************* This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you are not the intended recipient, please delete it and notify the sender. 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