The VENTANA HER2 Dual ISH DNA Probe Cocktail is intended to determine HER2 gene status by enumeration of the ratio of the HER2 gene to Chromosome 17 by light microscopy. The HER2 and Chromosome 17 probes are detected using two-color chromogenic in situ hybridization (ISH) in formalin-fixed, paraffin-embedded human breast and gastric carcinoma tissue specimens, including the gastroesophageal junction, following staining on BenchMark IHC/ISH instruments. The VENTANA HER2 Dual ISH DNA Probe Cocktail is indicated as an aid in the assessment of patients for whom Herceptin (trastuzumab) is being considered. This product should be interpreted by a qualified pathologist in conjunction with histological examination, relevant clinical information, and proper controls. The INFORM HER2 Dual ISH DNA Probe Cocktail is indicated as an aid in the assessment of patients for whom Herceptin (trastuzumab) treatment is being considered. It determines the qualitative presence of HER-2/neu gene amplification on formalin-fixed, paraffin-embedded human breast tissue as an aid to stratify breast cancer patients according to risk for recurrence or disease-related death.