Fig. 2: Optimization of RT–RPA and CRISPR-FDS assay conditions.
From: Liposome-mediated detection of SARS-CoV-2 RNA-positive extracellular vesicles in plasma
a,b, CRISPR-FDS assay signals from 5 µl PBS aliquots spiked with 100 copies of SARS-CoV-2 RNA and then incubated at 22, 37 and 42 °C for 15 min with 15 µl RT–RPA reagents and at 37 °C for 15 min with 50 µl CRISPR reagents (a) or at 37 °C for 15 min with 15 µl RT–RPA reagents and then at 22, 37 and 42 °C for 15 min with 50 µl CRISPR reagents (b). c, CRISPR-FDS signals detected with RNA isolated from EVs purified from 50 μl plasma aliquots of individuals diagnosed with or without COVID-19 by positive or negative nasal RT–qPCR results. NC, negative control; PC, positive control. d, CRISPR-FDS signals for RNA extracts obtained from healthy human plasma (50 μl) spiked with or without RNA or virions (>105 copies) of the indicated human respiratory viruses. Human coronavirus (HCoV)-OC43, -HKU1, -229E and -NL63; Middle East respiratory syndrome-associated coronavirus (MERS-CoV); severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and respiratory syncytial virus (RSV). The data represent the mean ± s.d. of three replicates.
