Measuring a Zeptogram
Here’s something for the “boggles the mind” category. Scientists have now created scales that are able to detect weights as small as a zeptogram (10^-21 g). That’s roughly the equivalent of a single protein molecule (yes, a molecule, people).
The key to the scales is a small blade that vibrates in a magnetic field, generating a voltage in an attached wire. When atoms or molecules are placed on its surface, they weigh it down, lower the vibration frequency and change the voltage.
The next step is to increase scale precision to yoctograms (10^-24 g) in order to be able to identify protein molecules by weight. The article suggests uses for such technology as the ability to diagnose disease by detecting marker molecules in a drop of blood or analyzing the inner workings of a single cell.