Abstract High-throughput analysis of a large number of samples can greatly benefit from sampling barcoding as it can significantly reduce reagent costs and batch error as well as increasing the acquisition speed. Optical barcoding with its readout compatible with fluorescence analysis offers compelling advantages over DNA barcoding because it allows rapid multiparameter analysis of each sample and does not rely on a binary ‘hit’ or ‘miss’ criterion. However, current fluorescence- based barcoding does not meet the current and future needs of massive-scale multiplexing. The goal of this project is to develop novel, highly scalable, optical multiplexing technology based on multi-color laser particles. A combination of several discoidal microparticles, each emitting a narrowband laser spectrum, can be tagged on the surface of cells or microbeads and serve as the unique identifiers of the objects. The first specific aim is to develop 50 color sets of semiconductor laser particles across a spectral range of 1150 to 1600 nm via microfluidic particle sorting. The second specific aim develops applications of this new tool in three major high- throughput analysis platforms: first, multiparameter flow cytometry of 384-pooled cell samples; second, 3840-plex bead immunoassays; and third, all-optical multiparameter screening of combinatorial one-bead-one-compound libraries. The breakthroughs in these high-throughput technologies are expected to facilitate numerous biological discovery applications including drug development.