Immunoassays and enzyme-linked immunosorbent assays (ELISA) are one of the key technologies for the quantification of a wide range of analytes for serum, plasma and cell lysates. The protocols of the immunoassays have not changed significantly for over 6 decades, as used extensively in both research and clinical applications. However, there is a large demand for the development of new protocols or platforms for immunoassays with rapid turnaround time (TAT), high sensitivity and low cost for high throughput drug screening, point-of-care clinical diagnostics, or rapid food safety monitoring. Recently, microfluidics and lab-on-a-chips (LOC) have been emerging as one of the most promising platforms for better immunoassays due to its distinctive natures enabling to meet the demands. In this talk, the distinctive natures of microfluidics and lab-on-a-chips are discussed as a new game changer for immunoassays and in vitro diagnostics (IVD), and then its applications to ELISA, IVD and point-of-care testing (POCT) clinical diagnostics are introduced