id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-342344-jjnf4yje	Mello, C. J.	Absolute quantification and degradation evaluation of SARS-CoV-2 RNA by droplet digital PCR	2020-06-26		.txt	text/plain	3122	190	55	Diagnostic assays for the presence of SARS-CoV-2 currently use real-time reverse transcriptase PCR (RT-qPCR) to yield a binary (positive or negative) result based on an amplification cycle threshold (Ct) value 9-12 . Current PCR-based assays can detect the presence of very short SARS-CoV-2 RNA sequences but do not distinguish whether these sequences are derived from longer molecules present in the sample at the time of collection. To address these issues, we explored using droplet digital PCR (ddPCR) 19, 20 to more precisely quantify SARS-CoV-2 RNA in biological samples and evaluate the extent to which positive results reflect larger, intact viral nucleic acids. The results yielded definitive evidence of linkage: although only 822 of the 12,220 droplets (6.7%) were positive for either N1 or N2, 75% of the droplets that were positive for N2 (HEX) were also positive for N1 (FAM) (Fig. 2a, Table 1 ); we estimate (using a formula we previously described 21 , which accounts for chance co-encapsulation) that 71% of the detected RNA sequences were physically linked.	./cache/cord-342344-jjnf4yje.txt	./txt/cord-342344-jjnf4yje.txt