Figure 1.

A: Sample preparation for FISH analysis. First, a 4-μm-thick section was cut and stained with H&E for the identification of regions containing DCIS and IDC. The second and third sections were 6 μm thick (for potential FISH or immunohistochemical studies), and the fourth and fifth sections were 50 μm thick and were used for the preparation of nuclei for FISH analysis. The sixth section was 4 μm thick and was also stained with H&E. After macrodissection and protease digestion, single-cell suspensions were transferred to slides as cytospin preparations and fixed for FISH analysis. B: Examples of H&E-stained sections of DCIS and IDC, shown here from case 5.