For trimming of the reads (i.e., removal of P7 Illumina adapter sequences), cutadapt (version 2.8) (42) was used. For validation of the origin of the sequence of the LAMP product (fig. S4A), 107 reads were randomly selected and used for the analysis. Reads were mapped to the SARS-CoV-2 reference genome (NC_045512.2) (43), using bwa-mem with default settings (version 0.7.17-r1188) (44). Virus genome coverage was determined with the samtools depth command (version 1.10) (45). Using bwa-mem, 80.6% of reads could be mapped to the virus genome (fig. S4, B and C). To analyze the remaining sequences, a k-mer analysis using a custom script was performed. Using 9-mers, this matched 93.5% of the nonmapped reads with a maximal Levenshtein distance of two to one of the LAMP primers or their reverse complement sequences (fig. S4D). This is explained by the fact that LAMP products can consist of complex sequence rearrangements.