The Weight of a Cell

This article explains how the weight of single cells, like yeast and E. coli, is measured with remarkable precision, despite their minuscule size. It details two primary methods: an early 1953 experiment that used Stokes' law, a microscope, and a camera to measure yeast cells in sugar water, and a more modern 2010 technique employing a "suspended microchannel resonator" to measure the buoyant mass and growth rate of individual bacterial cells with femtogram precision. The article highlights the elegance of using basic mathematics and first principles to tackle seemingly impossible scientific measurement challenges, drawing parallels to Lord Rayleigh's 19th-century calculation of molecule size.