What you describe is a typical example of poor paraffin infiltration = the paraffin has not infiltrated the tissue and when you prepare the final block it will consist of 2 different components; the tissue and the paraffin. That is why you end with a "good paraffin section" without the tissue. Poor paraffin infiltration is always caused by an improper sequence while tissue processing. Either the fixation is incomplete OR the dehydration is incomplete and there is water in the tissue when you go to the "clearing" stage OR the clearing stage is incomplete and the tissue still has alcohol (immiscible with paraffin) when the tissue goes to the paraffin OR the paraffin infiltration is too short. The problem resides in your processing protocol and there is nothing you can do about that at the end. Try to check your processing protocol to eliminate the problem. If this is happening "all of the sudden" while you used to have good results previously, then you either have changed reagents or the reagents are not in a good condition. René J.
________________________________ From: Megha Kumar <meg...@g.clemson.edu> To: histonet@lists.utsouthwestern.edu Sent: Tuesday, August 7, 2012 11:45 PM Subject: [Histonet] help ! paraffin section Hi All I am trying to section adult mouse intestine and skin using paraffin embedding. However, when i section, the tissue is torn although the rest of the paraffin looks perfect. Please suggest why this is happening. Also, sometimes the skin sections fall off the slides when I perform in situ hybridization. Any ideas how to prevent this? Please help! i am a beginner in histology and dont' know what to do! regards Megha * * _______________________________________________ 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
