DITHIOTHREITOL HOMOGENIZATION OF PREFIXED SPUTUM FOR LUNG-CANCER DETECTION

The technique of chemical homogenization of sputum for cancer detectio n was revisited. The mucolytic agent dithiothreitol (DTT) had been use d by the authors on fresh specimens. In this study, its effectiveness in homogenizing prefixed sputum was investigated. Fifty-seven positive samples were examine& 28 were prefixed with 2% carbowax in 60% ethano l and 29 in 3 % carbowax in 60% ethanol Each specimen was divided equa lly into three parts and homogenized immediately, 3 and 7 days later, respectively, with 0.2% (0.013 mol/L) DTT in the respective prefixativ e. Five samples were prefixed for 4 wk before homogenization. The homo genization time varied from 30 min to 48 hr. The cellular morphology w as compared to directly smeared controls from the same samples. It was found that the cellular morphology was well preserved and best with t he 3% carbowax in 60% ethanol. The specimen could be prefixed for up t o 4 wk before homogenization and the homogenization process could last from 30 min to 48 hr without any damaging effect on morphology. Furth ermore, screening was made easy with the mucus lysed and its obscuring effect removed and the cells concentrated and evenly distributed The method was versatile and could be of value in enhancing the defection rate of cancer in sputum. Diagn Cytopathol 1994;10: 76-81. (C) 1994 Wi ley-Liss, Inc.