It also depends by the thickness of the pieces. If they are small after about 20 minutes you can put them in new paraffin where they will still stay for 20 minutes. If the pieces have a medium thickness ( about a half of a cubic centimetre) it would be better to keep them in the oven altogether for two hours, by changing the paraffin after a hour. Pieces of organs or embryos with spacious cavity, bulky fragments of nervous system, fibrous tissues, they must remain in the heater more time so the paraffin can fill the empty spaces and to embed completely the tissues. For instance four hours in the first paraffin bath and the same in the second one. I use, before to processing, to put the pieces into a saturated solution of paraffin in the solvent ( Xylene in my case) for about a hour. Then I dry them with blotting paper before to put them into the first paraffin bath. But that it isn't a necessary step. Pay attention, when you have obtained the paraffin block with the enclosed pieces and you see a whitish ring around the enclosed pieces it means that not all the solvent was taken away from the first paraffin bath and it was dragged in the following baths. In that case it is advisable to repeat quickly the inclusion in a new paraffin. NOTE: I perform all the procedure in manual mode and not automatically.
Kind Regards, Massimo Tosi -------------------------- A humble Chemical Engineer histlogist. ________________________________ Da: Demetria Ross <[email protected]> A: [email protected] Inviato: Venerdì 28 Settembre 2012 0:21 Oggetto: [Histonet] Paraffin and Tissue I'm curious to know how long can tissue stay on the machine in paraffin before it becomes a problem I have left tissue stay in paraffin 30 min-2 hours before I take it off but not on a daily basis Thanks in advance _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet _______________________________________________ Histonet mailing list [email protected] http://lists.utsouthwestern.edu/mailman/listinfo/histonet
