Liquid crystals for DNA analysis

According to researchers from the USA, liquid crystals can undergo changes in their organization in response to a slight change in the primary structure of DNA, including mutations at the level of one nitrogenous base.

The discovery could lead to the creation of inexpensive, portable alternatives for existing DNA detectors.

Daniel Schwartz from the University of Colorado demonstrated that liquid crystals, usually located perpendicular to the surface of a glass plate covered with a layer of surfactant, tilt slightly when short strands of single-stranded DNA are added to them (left). The addition of a complementary DNA strand causes the tilted crystals to return to their original orthogonal position on the surface (right).

The addition of a non-complementary DNA strand (even if the difference is determined by only one nucleotide) does not cause such a response. The most important thing is that the change in the organization of liquid crystals can be observed with the naked eye.

Fluorescent methods are currently used for DNA microanalysis, but Schwartz notes that the technique he developed does not require the introduction of fluorescent tags into the samples of the DNA under study, and can also do without bulky lasers and photodetectors, while determining DNA point mutations with the effectiveness of classical methods.

The above research results are still a "demonstration of the possibility", a lot of work is still needed to commercialize the technology. Nevertheless, Schwartz is confident that on the basis of the new technique it will be possible to create a portable analytical device, the size and price of which will be comparable to a conventional wristwatch with a liquid crystal display powered by a simple battery.

ChemPort.Ru Based on J. Am. Chem. Soc., 2008, 54, 391 (DOI: 10.1021/ja0774055)

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