Introduction Microfluidic Total Analysis Systems (µTAS) miniaturize and automate immunoassay procedures by integrating reaction and electrophoretic separation within microchannels, enabling the concentration and separation of immunocomplexes. Since 2009, the µTASWako i30 system has been used to measure biomarkers of hepatocellular carcinoma (HCC), such as AFP, AFP-L3%, and PIVKA-II, using a fluorescence immunoassay based on the liquid-phase binding assay-electrokinetic analyte transport assay method combined with isotachophoresis (ITP) and capillary gel electrophoresis (CGE). This technique enables simultaneous quantitative and qualitative analysis of glycosylation variants exemplified by AFP-L3. The µTASWako i30 system, however, has limitations in throughput and measurement range for clinical samples with high biomarker concentrations. The µTASWako i50 system, a successor device, introduces modifications such as increased measurement speed and automatic sample dilution to address these issues. This study aims to evaluate the analytical performance of the µTASWako i50 system compared with the µTASWako i30. Methods The µTASWako i50 system retains the microfluidic immunoassay principles of the i30. Sequential operations of dispensing, immune complex formation, ITP stacking, and CGE with laser-induced fluorescence detection are performed on disposable plastic chips. Modifications include accelerated processing and an automated dilution function for samples exceeding assay linearity. Analytical parameters such as sensitivity, reproducibility, linearity, and correlation with the i30 system were assessed using an appropriate combination of standard solutions, control materials, and clinical serum samples from patients with chronic liver diseases, including hepatitis, cirrhosis, and HCC. Thereby, traceability of measurement values to the predecessor system was also examined. Results Analytical performance of the µTASWako i50 was found to be comparable to that of the i30 system with respect to sensitivity, reproducibility, and linearity across the tested biomarkers. The automated dilution function extended the measurement range, enabling quantitative analysis of samples with elevated biomarker levels without manual dilution. Correlation of measurement values between the two systems showed high agreement, and assay throughput was increased while turnaround time was reduced under the tested conditions using the µTASWako i50 system. Conclusions The use of the µTASWako i50 should enhance laboratory workflows by increasing processing efficiency and minimizing manual handling. The system provides reliable analytical performance comparable to its predecessor, thereby supporting consistent longitudinal clinical measurements of key biomarkers. Furthermore, the µTASWako i50 has the potential to improve clinical utility through an expanded measurement range and operational automation and may facilitate ongoing research into cancer biomarkers characterized by alterations in glycosylation patterns.
Yoshikawa et al. (2026) studied this question.