Work

Development and validation of a chemiluminescent immunoassay for TPA on the MAGLUMI platform: Alleviation of magnetic bead steric hindrance and clinical application

Year: 2026

Type: article

Abstract: A fully automated chemiluminescent immunoassay (CLIA) for tissue polypeptide antigen (TPA) was developed and validated on the MAGLUMI platform to alleviate the magnetic bead steric hindrance encountered in conventional direct-conjugation systems. The assay adopted a biotin-streptavidin mediated sandwich format: biotinylated capture antibodies were immobilized on streptavidin-coated magnetic beads to form stable Biotin-SA complexes, which effectively reduced steric hindrance and improved the accessibility of antigen-binding sites compared with direct conjugation. N-(4-aminobutyl)-N-ethylisoluminol (ABEI) was selected as the chemiluminescent substrate, whose signal intensity is positively correlated with the amount of captured TPA, enabling accurate quantification. Key parameters including reaction buffer, reagent concentrations, and anti-biotin blocking agent were systematically optimized. The optimized assay exhibited satisfactory precision (intra- and inter-assay CV < 10%), a limit of detection of 6.000 U/L, and a wide linear range of 9.000–6000.000 U/L with good linearity (R 2 > 0.990). Methodological comparison with the commercial LIAISON® TPA®-M assay using Passing–Bablok regression and Bland–Altman analysis showed high consistency (R 2 = 0.978). Clinical validation with 177 tumor samples and 301 healthy controls showed that TPA levels could effectively distinguish tumor patients from healthy individuals. Dynamic monitoring of 87 lung cancer patients revealed a significant decrease in postoperative TPA levels, indicating its potential in evaluating tumor resection efficacy. This study innovatively resolves magnetic bead steric hindrance via the Biotin-SA sandwich format and optimizes analytical parameters systematically. The developed fully automated TPA-CLIA, with high sensitivity, good precision and wide linear range, provides a robust analytical tool for TPA detection and has important application value in clinical tumor management.

Source: Results in Chemistry

DOI: 10.1016/j.rechem.2026.103734