Analysis and diagnosis in a chip format are coming of age, but their practical application has been limited because until now, the sample usually had to be prepared separately and on a nonminiaturized scale.
Jürgen Pipper and his team at the Institute of Bioengineering and Nanotechnology in Singapore want to change this. They have now developed a rapid test for genetic diagnosis that combines the preparation of biological samples with a polymerase chain reaction (PCR) on one chip. As they report in the journal Angewandte Chemie, the "laboratory device" for all steps in this system is a single drop containing magnetic nanoparticles, which is moved across the chip by a magnetic field.
PCR allows gene sequences to be duplicated and identified-to identify a disease trigger, for example. In this process, the sample must cycle through a specific sequence of temperatures. Because of the slow heating and cooling processes, laboratory PCR usually takes several hours. The new chip PCR requires only minutes, including for the sample preparation.