First I would determine if it is really DNA streaming out of the nuclei. Stain the sections with the Feulgen-Rossenbeck method, then I would also review the speed of freezing the tissue before FS, usually freezing time produce many artifacts in the final sections. René J.
--- On Sun, 1/4/09, Pritchard, Michele <prit...@ccf.org> wrote: From: Pritchard, Michele <prit...@ccf.org> Subject: [Histonet] DNA streaming out of nuclei in frozen sections? To: histonet@lists.utsouthwestern.edu Date: Sunday, January 4, 2009, 1:37 PM Hello: I have recently begun to use frozen sections to localize an antigen found in mouse liver tissue. My previous experience has been almost exclusively with staining of formalin-fixed, paraffin-embedded tissues. I have done two runs of this new staining protocol and noticed an odd artifact in both runs. It appears as though there are stringy stars throughout the sections! The 'strings' seem to originate from the hepatocyte nuclei leading me to believe that what I am seeing is DNA that has escaped the confines of the nucleus and is streaming out over the tissue. I did not squish or drag the coverslips onto/over the sections; this is the only thing that I could imagine would make such a mess. Does anyone have any information on the nature of this artifact and how to prevent it? I will be happy to provide my protocol or a picture if this is an odd artifact with which no one has experience. I suspect, however, that this is a 'newbie' mistake so I will refrain from posting any additional information at the present time. Thanks for your help. ---M.T. Pritchard Michele T. Pritchard, Ph.D. Research Associate Nagy Laboratory Department of Pathobiology/NE40 Lerner Research Institute Cleveland Clinic 9500 Euclid Avenue Cleveland, OH 44195 phone: 216.444.8613 fax: 216.636.1493 email: prit...@ccf.org Lab location: Lerner Research Institute NE4-214 =================================== P Please consider the environment before printing this e-mail Cleveland Clinic is ranked one of the top hospitals in America by U.S. News & World Report (2008). Visit us online at http://www.clevelandclinic.org for a complete listing of our services, staff and locations. Confidentiality Note: This message is intended for use only by the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. Thank you. _______________________________________________ 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