Illumina launched an early-access research-use-only duplex sequencing workflow aimed at ultra-sensitive detection of circulating tumor DNA for molecular residual disease (MRD) and tumor evolution studies. The kits are expected to ship in the first quarter of 2027 and target settings where tumor shedding or mutation burden is low. The workflow uses duplex chemistry to confirm each base call using both complementary strands, increasing confidence that detected variants are biological rather than library or sequencing artifacts. Illumina said quality scores above Q65 are achievable on NovaSeq X, with DRAGEN generating duplex consensus reads and interrogating thousands of tumor-specific variants across the genome using 5–10 ng cfDNA input. Representative studies reported detection down to 2.5 parts per million, and NYU Langone Health is listed among early adopters. The launch strengthens the sequencing toolchain available to MRD investigators competing on sensitivity and longitudinal reproducibility.