Interphase FISH analysis in relation to allelic state analysis.

<p>In FTC-OV, chromosome 6 was always observed in allelic state [A] or [AA], whereas chromosome 7 was always retained in a heterozygous state or amplified heterozygous state. To confirm these results, interphase FISH was performed for chromosomes 6 and 7. Examples are shown, see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0038287#pone-0038287-t001" target="_blank">Table 1</a>. <b>A</b>. FISH on normal thyroid epithelium. <b>B</b> and <b>C</b> show FTC-OV case No. 10. <b>B</b>: Allelic state analysis illustrating allelic state [A] for chromosome 6 and allelic state [AABB] for chromosome 7. <b>C</b>. Left panel: green signal, centromere 6 shows 1 copy, confirming the allelic state [A] in three of the four nuclei. Right panel: four green and four red signals representing EGFR and centromere 7, respectively and confirming the [AABB] allelic state. <b>D–E</b> show FTC-OV, case no 11. <b>D</b>. The allelic state [AAB] of chromosome 7 could not be confirmed definitively and showed a mixture of nuclei containing three green (EGFR) and three red (centromere) signals or four green and four red signals, respectively (<b>E</b>). This may be due to intra-tumour heterogeneity.