The RNAscope® 2-plex Chromogenic Assay is based on ACD’s patented signal amplification and background suppression technology. The assay uses a novel and proprietary method of in situ hybridization (ISH) to visualize single RNA molecules per cell in FFPE samples mounted on slides. RNAscope® Assays do not require the RNA-free environment used for traditional ISH. The RNAscope® 2-plex Chromogenic duplex assay is ideal for simultaneous detection of two RNA species using RNA ISH. It uses HRP (Green) and Fast Red chromogenic stains and the probe names often include C1 or C2. The stained slides are visualized with brightfield microscopes.