Chip-based heterogeneous immunoassay for clinical diagnostic applications

摘要

A rapid heterogeneous immunoassay based on a glass chip integrated microfluidic system for clinical diagnostic application is described. The probe molecules are immobilized directly onto the surface of a reaction chamber. Based on electroosmotic pumping and valveless fluid control handling, sample solution is pumped over the active surface of the reaction chamber during incubation. Excess of sample is rinsed off electrokinetically before a low pH buffer solution is introduced to mobilize the bound sample to be detected. To characterize the method with respect to reproducibility, flow rate, incubation time, reactor volume and geometry, a model system with surface immobilized Protein A and Cy5-labeled rabbit IgG has been chosen. The strong affinity of Protein A for rIgG leads to rIgG binding to the surface, in quantities proportional to its concentration in solution.