Figure 1.

From lab on a chip to lab on a particle. (a) Lab on a chip technology uses microchambers or droplets to confine reactions, enabling the analysis of target cells or molecules with high precision. Parallelization and scale-up rely on the 2D surfaces of chips and custom instrumentation, which often lead to reduced analysis throughput. (b) Lab on a particle technology enables millions of microparticle-based compartments to be scaled in 3D in standard tubes, where fluidic operations are performed using standard laboratory equipment. (c) Operations on particles include cell loading and encapsulation, analyte binding, reagent exchange and washing, and templating of water-in-oil emulsions. Signal enrichment can occur on particles through reactions that are either confined or locally bound. Microparticles are barcoded by shape, size, pattern, color, or other means to enable time-variant analysis as reactions or cell behavior progresses over time. (d) Microparticles are analyzed using standard analytical instruments compatible with cells, such as microscopes, flow cytometers, fluorescence activated cell sorters and single-cell sequencing instruments.