Researchers in Europe have invented a new hypersensitive scale that can be used to measure fluctuations in living cells in real-time, Digital Trends reports. The Cytomass Monitor can measure the weight of a single cell weighing only two or three nanograms. (A nanogram is one billionth of a gram.)

Developed by researchers at ETH Zurich, the University of Basel, and University College London, the Cytomass Monitor works by monitoring the changing resonant frequency of a cantilever.

A pulsing blue laser pointed at the microscopic cantilever causes it to oscillate. When the cantilever—made sticky by collagen or a binding protein called fibronectin—picks up an individual cell, researchers can determine its weight by the way that the resonant frequency changes, which is read by an infrared laser. The device is made to be placed directly on the plate of a microscope, so the user can also see and film the cells moving.

In a new study published in the journal Nature, the researchers use the super-sensitive scale to show that a mammalian cell's mass subtly fluctuates throughout the cell cycle. On a second-to-second basis, a living cell's weight fluctuates by between 1 and 4 percent of its total weight, they found.

A Swiss technology company called Nanosurf is now working to make the Cytomass Monitor commercially available so that it can be used in a range of biological and pharmacological research. You can see the concept illustrated in the video below.

This is not, however, the most sensitive scale ever built. In 2012, researchers created a scale capable of measuring the mass of a single proton. 

[h/t Digital Trends]