New technique for processing paraffin-embedded tissue for Y chromosome fluorescence identification of trophoblastic...

A new reprocessing technique for Y chromosome fluorescent body (q 12 region) detection of trophoblastic disease in previously paraffin-embedded tissues is described. Deparaffinized sections were treated with pronase and trypsin for digestion, followed by hydrolysis with HCl and acetic acid, staining with quinacrine hydrochloride fluorochrome and mounting in Sørensen's phosphate buffer (pH 5.5). Use of the technique resulted in sufficient fluorescence quality and better accuracy for Y and X heterochromatin scoring. The technique yielded the same results in retrospective formalin-fixed, paraffin-embedded trophoblastic specimens as in fresh tissues. The combinations of enzymes and acids and the dosages necessary for optimal results are discussed.