Figure 1.

Brightfield double in situ hybridization (BDISH) signal detection scheme with a sequential in situ hybridization method. HER2 gene signal was detected with a DNP-labeled nick translated DNA probe hybridization followed by silver signal detection system (silver acetate, hydroquinone, and H₂O₂ reaction). Then, chromosome 17 centromere (CEN 17) signal was detected with a DNP-labeled CEN 17 oligoprobe hybridization followed by fast red and naphthol phosphate reaction signal detection system.