A Nature Communications paper from Ma and Kim introduces the dilution-and-delay (DnD) susceptibility assay, a high-resolution, high-throughput method designed to detect low-frequency or inducible antibiotic resistances that standard tests miss. The DnD assay amplifies subtle phenotypes by controlling growth-delay dynamics and antibiotic exposure, enabling earlier detection of resistance variants and tolerance states. If adopted by clinical microbiology labs and CROs, the DnD approach could change empirical therapy decisions, speed identification of emerging resistance mechanisms and support antibiotic-development pipelines by improving preclinical screening sensitivity.