Molecular Detection of SARS-CoV-2 in Formalin Fixed Paraffin Embedded Specimens

Xiankun Zeng; Jun Liu; April Babka; Brian Kearney; Sheli Radoshitzky; Jens Kuhn

SARS-CoV-2 detection in FFPE specimens 12 were rinsed, and the peroxidase-labeled polymer (secondary antibody) was applied for 30 min. Table 2 ). Tissue sections were deparaffinized with xylene, underwent a series of 214 ethanol washes and peroxidase blocking, and were then heated in kit-provided antigen retrieval 215 buffer and digested by kit-provided proteinase. Sections were exposed to ISH target probe pairs 216 and incubated at 40°C in a hybridization oven for 2 h. After rinsing, ISH signal was amplified 217 using kit-provided Pre-amplifier and Amplifier conjugated to alkaline phosphatase and incubated 218 with a Fast Red substrate solution for 10 min at room temperature. Sections were then stained 219 with hematoxylin, air-dried, mounted, and stored at 4°C until image analysis. Table 1 ) overnight at 4°C, 237 following the Fast Red substrate ISH procedure described above using positive-sense RNA probe 238 2 (Supplemental Table 2 ). One day later, sections were rinsed, and the peroxidase-labeled The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.21.042911 doi: bioRxiv preprint The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.21.042911 doi: bioRxiv preprint Liu et al. The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.04.21.042911 doi: bioRxiv preprint Supplemental Tables 418 Supplemental Table 1