Polymerase chain reaction in almost unreal time

Preparation of a sample for PCR analysis takes longer than the polymerase chain reaction itself. The lab-on-a-chip, developed in the group of Jurgen Pipper from the Institute of Bioengineering and Nanotechnology of Singapore, can perform PCR in raw DNA samples in real (and record-breaking) time.
In the figure from the article Juergen Pipper et al. Clockwork PCR Including Sample Preparation (Angewandte Chemie International Edition) – "laboratory" in full size: the white stripe in the left corner of the upper panel is a 10-millimeter scale. And how it works, you can see on three short videos.

The new technique makes it possible to purify the sample directly in the chip by binding magnetic nanoparticles carrying antibodies specific to certain proteins with sample cells whose membrane contains the corresponding proteins. After that, the cells of interest to researchers using a magnet are extracted from the sample (covered with a layer of mineral oil drops of blood with a volume of 25 microliters), and placed in another drop in which the cells are washed of all excess, and then – in the next and last, containing the necessary set of enzymes and nucleotides.

For PCR, a certain temperature regime is required – cycles of heating and cooling the solution. To do this, the nanoreactor drop is moved by a magnet into wells in which the desired temperature is maintained. The negligible volume of the reactor droplet (only 1.5 µl) allows it to be heated and cooled at a high speed: the entire DNA doubling cycle takes place in 8 seconds. After each cycle, a fluorescent technique is installed.

The whole process from placing the sample in the chip to determining the gene takes 17 minutes. The researchers showed this on a blood sample containing a total of 30 cells synthesizing green fluorescent protein in a volume of 25 µl.

Portal "Eternal youth" www.vechnayamolodost.ru based on IBN materials

13.05.2008