Researchers Ma and Kim published a Nature Communications paper introducing the dilution‑and‑delay (DnD) susceptibility assay, a high‑resolution, high‑throughput method that uncovers bacterial resistances missed by conventional tests. The DnD assay profiles temporal and concentration responses, exposing heteroresistance and slow‑growing subpopulations that evade standard susceptibility workflows. The technique scales to large sample sets and offers clinicians and researchers finer granularity on resistance mechanisms, potentially informing targeted therapy choices and surveillance. The authors demonstrated DnD’s ability to reveal clinically relevant resistances across multiple bacterial species and antibiotic classes. If adopted in clinical microbiology labs, DnD could change how susceptibility data guide antibiotic selection and stewardship programs; operational validation and regulatory pathways will determine how quickly the method reaches routine use.