Colorimetric stack pad immunoassay for bacterial identification

摘要: A new colorimetric immunoassay concept, utilizing conventional lateral flow membranes (e.g., conjugation, sample, absorption and nitrocellulose), were placed in a different configuration stacking manner, where the liquid sample that may contain analyte diffuses from bottom to upper-most layer. The key element of this proprietary technology is capture layer, nitrocellulose membrane modified with target interest, namely study Escherichia coli. During operation, samples contaminated bacteria will conjugate their corresponding HRP-antibodies laying wait immune-target measurand complex flows by capillarity towards layer generate signal (positive answer) through an enzymatic reaction. In target-free samples, previously immobilized on prevent HRP-labeled anti-target antibodies migrating substrate lays wait. After optimization, sensitivity approach was found be 1,000 folds higher than ELISAs (102cellsmL-1). advantages stacked pad assay include: miniaturization, operational simplicity, fast response time (less 5min), useful sensitivity.