Tracking drugs in single cells

A non-invasive method to quantify water in living cells is being pioneered in Germany.

Intracellular water concentration is a good indicator of disease and cell abnormalities. But since water molecules are too small to be tagged, Erik Br?ndermann and his colleagues at Ruhr-University, Bochum, have developed a label-free method using near infrared microscopy with a diode laser source. This offers advantages over other analytical techniques, such as fluorescence and NMR, and high precision can be achieved since water absorbs strongly in the infrared region.

Liver cells shrink and swell to different extents when the incubation buffer concentrations are varied. The resulting osmotic pressure changes illustrate the effects that biochemicals have on the water concentration in cells. High speed IR imaging can monitor fast intracellular fluxes, and Br?ndermann anticipates that with advancing technology there is great potential for medical applications in the future, saying that their goal is to ’monitor the influence of minimum dosages of pharmaceuticals on a single cell level in real-time’.

Carolyn Ackers