[Flow cytometric quantification of numerical chromosome aberrations in non-small cell lung carcinomas using...

Fluorescence in situ hybridization with biotinylated repetitive DNA probe specific for the centromeric region of chromosome 17 (p17H8: Oncor) was applied to suspended nuclei which were isolated by Shutte's method from formalin-fixed paraffin-embedded tissue. The tissues were obtained from surgically resected specimens from nine patients with non-small cell lung carcinoma. The isolated nuclei were prepared with 0.05% pepsin/0.1NHCl for 15 minutes at 37 degrees C. Subsequently, these were immersed in 70% acetic acid for 10 seconds at room temperature. After heat denature with hybridization mixture which contained 3 mu 1 DNA probe for 10 minutesat 70 degrees C, 1 x 10(6) nuclei were incubated overnight at 37 degrees C. After washing with 60% formamide/2 x SSC, the hybridized probes were labeled by FITC conjugated avidin. A number of centromeric signals of chromosome 17 wasevaluated by fluorescence microscopy (BH-2, Olympus). Furthermore, a probe-related FITC intensity was quantified using flow cytometry (FACScan, Becton Dickinson). As the results, there was good correlation between a relative fluorescence intensity determined by flow cytometry and a relative fluorescence signal by fluorescence microscopy (p < 0.05).