(a) Polyacrylamide electrophoresis could not recognise a target to use in current MRD methodologies (well 1 containing the products from a PCR reaction that would amplify VH1 and VH7, and wells 2-6 amplifying VH2-6, respectively), while the NGS pipeline could identify a VH7 rearrangement (b). (c) ASOs were designed to amplify the NGS-identified VH7-81*01 DH3-9*01 JH4*02 rearrangement and optimised to correctly identify 10^-2, 10^-3, 10^-4 dilutions with a single NAC (non-amplification control; monocytes from 20 normal individuals) replicate amplified, therefore meeting current guidelines for a MRD target.