Tissue Specimen Requirement
FFPE Tissue Block Preparation
Tissue specimens should be blocked into a thickness of 3 - 4 mm and fixed for 24 +/- 8 hours in 10% neutral-buffered formalin at room temperature. The fixed tissues should then be dehydrated in a graded series of ethanol and xylene, followed by infiltration by melted paraffin held at no more than 60°C. Properly fixed and embedded tissues that were prepared within the last three years have close to 100% success rate in the RNAscope® FFPE assay. The RNAscope® assay kit is specifically developed for formalin-fixed tissues only.
Tissue Slide Preparation
Tissue specimens should be cut into sections of 5 +/-1μm and mounted on Superfrost Plus slides. Specimens should be analyzed within 3 months of sectioning when stored at room in desiccant temperature (20-25 °C). Slides need to be air dried and baked at 60°C for 1-2 hours prior to the RNAscope® FFPE assay.
Different Tissue Types
Different types of tissue specimens may need different pretreatment conditions for optimal assay results. Guidelines are provided in our product manuals for breast, colon, lung, and prostate tumor tissue specimens, however assay conditions for other specimens, including tissue types, normal tissues, frozen specimens or non-human species may need further optimization. Please consult product support at support@acdbio.com for additional guidance.
Tissue Specimens Not Conforming To Specimen Requirement
Many tissue specimens not conforming to above guideline may still work on our RNAscope® FFPE assay with or without further assay optimization. However, under-fixed tissue specimens (e.g. fixed in 10% NBF for less than 12 hrs at RT) do not work well. Please consult product support at support@acdbio.com for further assay optimization.

