Chen, Po-HsunPo-HsunChenWang, Lin-YuLin-YuWangChang, Chia-YuanChia-YuanChangChien, Yuh-ShiuanYuh-ShiuanChienSu, Yu-ChiaYu-ChiaSuWang, Chi-KuangChi-KuangWangKUANG-CHONG WUChin, Hsian-JeanHsian-JeanChinCHIEN-FU CHEN2025-11-252025-11-252025-11-1513858947https://www.scopus.com/record/display.uri?eid=2-s2.0-105018574030&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/734140High-throughput drug screening is critical in discovering therapeutic compounds, but traditional manual dilution methods are laborious, error-prone, and inefficient. Here, we report on the development of a microfluidic device designed to generate drug concentration gradients accurately and rapidly. This device utilizes laminar flow at low Reynolds numbers to precisely control the volume ratio of the two mixed fluids by adjusting channel length, helping to create precise dilution ratios from 1/3× to 1/300×. We demonstrated that the resulting concentration gradient deviated less than 6 % from the target value, significantly better than manual dilution methods, using bovine serum albumin (BSA) as a sample to simulate actual drug dilution. Furthermore, the device was validated through cytotoxicity tests of the dilution of chemotherapy drug (oxaliplatin) on colorectal cancer cells (HCT-116). The IC50 deviation obtained from the microfluidic device was within 2.45 % of those obtained by manual dilution, showcasing its reliability and accuracy. Multi-drug screening involving 5-FU, oxaliplatin and SN-38 on HCT-116 cells was also conducted to demonstrate the device's applicability in complex screening. Notably, the device achieves steady-state within 30 s at high flow rates, demonstrating scalability and potential for integration into high-throughput screening platforms. This technology reduces the time and labor required for drug screening and improves dilution accuracy, providing a promising avenue for personalized and precision medicine.falseDrug concentration gradientDrug dilutionHigh-throughput screeningMicrofluidic devicePrecision medicine[SDGs]SDG3journal article10.1016/j.cej.2025.1695102-s2.0-105018574030