RT Journal Article SR Electronic T1 Detection of EGFR deletion using unique RepSeq technology JF bioRxiv FD Cold Spring Harbor Laboratory SP 584045 DO 10.1101/584045 A1 Thuraiayah Vinayagamoorthy A1 Dahui Qin A1 Fei Ye A1 Minghao Zhong YR 2019 UL http://biorxiv.org/content/early/2019/03/20/584045.abstract AB We are reporting a novel sequencing technology, RepSeq (Repetitive Sequence), that has high sensitivity, specificity and quick turn-around time. This new sequencing technology is developed by modifying traditional Sanger sequencing technology in several aspects. The first, a homopolymer tail is added to the PCR primer(s), which makes interpreting electropherograms a lot easier than that in traditional Sanger sequencing. The second, an indicator nucleotide is added at the 5’end of the homopolymer tail. In the presence of a deletion, the position of the indicator nucleotide in relation to the wild type confirms the deletion. At the same time, the indicator of the wild type serves as the internal control. Furthermore, the specific design of the PCR and/or sequencing primers will specifically enrich/select mutant alleles, which increases sensitivity and specificity significantly. Based on serial dilution studies, the analytical lower limit of detection was 1.47 copies. A total of 89 samples were tested for EGFR exon 19 deletion, of which 21 were normal blood samples and 68 were samples previously tested by either pyrosequencing or TruSeq Next Generation Sequencing Cancer Panel. There was 100 % concordance among all the samples tested. RepSeq technology has overcome the shortcomings of Sanger sequencing and offers an easy-to-use novel sequencing method for personalized precision medicine.