The Yenos/MinION Multi-Cancer Early Detection Liquid Biopsy Test: An Innovative Approach to MicroRNA Quantification.

The MinION from Oxford Nanopore Technologies was repurposed to detect and quantify microRNAs (miRNAs) in total RNA isolated from serum or urine samples. Detection and quantification were enabled with a proprietary probe, complementary to the target miRNA, enhanced with osmium tags. The assay yields absolute miRNA copies, at the femtomolar (fM) level, per 1 μL of total RNA isolate with up to ±20% accuracy. This unprecedented accuracy is the result of a bracketing experimental protocol where one experiment is designed to include about 20% more probe and the other experiment about 20% less probe than the target miRNA. Several miRNAs, quantified in a commercial combined serum from healthy men and in the urine of healthy volunteers, exhibited comparable copy numbers after normalization to the same total RNA content. These observations refute the belief that the collection method and the subject's demographics cause sample variability. Our ready-to-use platform discriminated healthy from cancer samples based on miRNA overexpression. Preliminary results suggested that known cancer biomarkers, such as miR-21, miR-375 and miR-141, are approximately 1.8-fold elevated in prostate, pancreatic, breast, ovarian, colorectal, and lung cancer indications than in healthy samples. The latter led us to exploit 1.5-fold the healthy level (1.5 HL) as the threshold to discriminate healthy from cancer samples with zero data overlap (the Yenos test). Materials and methods to conduct this test are described below.