Individual ESBL synthetic quantitative standards are designed to support precise assay calibration and thorough validation of molecular diagnostics targeting the blaSHV (2, 5, 15), blaPER (5, 6), blaGES (5), blaTEM, and blaCTX-M gene variants. Supplied at three defined concentrations—high (10,000 copies/µL), medium (1,000 copies/µL), and low (100 copies/µL)—these standards enable accurate generation of standard curves and evaluation of assay linearity across a broad dynamic range. They support determination of amplification efficiency, analytical sensitivity, and limits of detection in PCR and real-time PCR workflows. Consistent and well-characterized, the standards aid routine quality control, inter-run comparability, and assay troubleshooting. Incorporation of these quantitative standards ensures confidence in quantitative results and reliable detection of clinically relevant ESBL gene variants in research and diagnostic molecular applications (RUO)