Carbapenem-resistant Enterobacterales (CRE) pose severe challenges to hospital infection control. Rapid and accurate detection of carbapenemases enables timely identification of enzyme-producing resistant strains, rational antimicrobial medication and containment of resistant pathogen transmission. Immunoassay-based rapid carbapenemase test kits have been widely adopted in microbiology laboratories for simple operation and fast turnaround. Nonetheless, reagent developers commonly face bottlenecks in calibrator and quality control (QC) raw material selection. Commercially prevalent recombinant protein antigens differ markedly in folding conformation from native carbapenemases expressed by clinical strains. Calibration and QC systems prepared from such antigens tend to suffer poor commutability and result drift across platforms and batches. Native antigens are thus preferred for calibrator & QC preparation: they retain the native conformation of bacterial proteins, mimic antigen profiles in clinical specimens, and fundamentally improve assay commutability.