Detecting the Genetic Variation between Individuals (2011.2.28)
As it is better to wear clothes that fit you well rather than to try on many possible sizes, it is also most prudent to take pills that cure your ailments precisely without triggering unwanted side-effects. A POSTECH joint research team has contributed to the forthcoming era of customized medicines by developing a very precise way to detect the genetic variations among individuals. The team has made it possible to prescribe appropriate therapeutic administrations for each individual. This new technology can assign the most appropriate pills for a cold, anticipate the effects of new anti-cancer medication, and prevent heparin accidents that claim three percent of the death toll for medical accidents.
Professor Jin Kon Kim with Postdoctoral researcher Dr. Seung Yun Yang, researcher at Harvard University and Professor Won Jong Kim with PhD candidate Sejin Son initiated a joint project on the detection of Single Nucleotide Polymorphisms (SNP). The team used a very dense nanochannel made of block copolymers and successfully detected an SNP with high resolution without using any complicated physical chemistry. This novel work has been reported in Nano Letters (11(3), 1032-1035 (2011)), a worldrenowned science journal of high potential impact on future therapies, and in Nanowerk, an international online magazine focusing on Nanoscience and technology.
The invented nanochannel is 15 nm in diameter, which is only one ten-thousandth of a strand of hair, and can fix nucleic acid with at least two-fold higher precision than the conventional DNA chip technology. The ultrahigh density of such nanochannels and alignments allowed an enhanced and accurate detection of the SNP.
A conventional DNA chip had limited surface that could only fix a limited number of nucleic acid on its surface. It also used a stationary solution, which entailed a long duration for analysis and was sensitive to certain changes in its surroundings such as temperature and salt concentration. Furthermore, expensive enzymes are necessary for a special analysis tool, which invariably limits the commercialization of such chips for wide and practical application.
The research team continuously injected the DNA solution into the nanochannel, and with sequence-specific DNA hybridization, they were able to achieve a higher degree of detection. Moreover, the team used double stranded DNA instead of single stranded DNA as a probe, which allowed them to accurately detect whether the sample DNA was mutant or not, and also the location of the variation. Such an attempt to attach a probe with double stranded DNA to a highly dense nanochannel to detect a highly sensitive SNP was originated by this POSTECH team.
Specialists anticipate that an accurate analysis of the genetic differences between individuals will allow medicine to be customized to a certain extent. Considering the fact that over 90 percent of drugs work on only 30 to 50 percent of its takers, this achievement can greatly decrease the number of side-effects or medicinal accidents. As a representative, Professor Jin Kon Kim stated, “Our SNP detection system can eliminate any adhered genes after analysis apart from its detection function. I am confident that our work could also be applied to the detection and refining process of various biomolecules and to all sub-fields of life science.” This research was supported by the Korean Ministry of Education, Science and Technology.