MIT engineers have devised a way to measure the mass of particles with a resolution better than an attogram—one millionth of a trillionth of a gram. Weighing these tiny particles, including both synthetic nanoparticles and biological components of cells, could help researchers better understand their composition and function.

The system builds on a technology previously developed by Scott Manalis, an MIT professor of biological and mechanical engineering, to weigh larger particles, such as cells. This system, known as a suspended microchannel resonator (SMR), measures the particles’ mass as they flow through a narrow channel.

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