Abstract-Terahertz molecular resonance of cancer DNA

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• Hwayeong Cheon
• , Hee-jin Yang
• , Sang-Hun Lee
• , Young A Kim
•  & Joo-Hiuk Son

http://www.nature.com/articles/srep37103

Carcinogenesis involves the chemical and structural alteration of biomolecules in cells. Aberrant methylation of DNA is a well-known carcinogenic mechanism and a common chemical modification of DNA. Terahertz waves can directly observe changes in DNA because the characteristic energies lie in the same frequency region. In addition, terahertz energy levels are not high enough to damage DNA by ionization. Here, we present terahertz molecular resonance fingerprints of DNA methylation in cancer DNA. Methylated cytidine, a nucleoside, has terahertz characteristic energies that give rise to the molecular resonance of methylation in DNA. Molecular resonance is monitored in aqueous solutions of genomic DNA from cancer cell lines using a terahertz time-domain spectroscopic technique. Resonance signals can be quantified to identify the types of cancer cells with a certain degree of DNA methylation. These measurements reveal the existence of molecular resonance fingerprints of cancer DNAs in the terahertz region, which can be utilized for the early diagnosis of cancer cells at the molecular level.

Off Topic-Bio-NEMS Corporation Announces Strategic Partnership with In-Q-Tel

My Note: I came across this news release today, and wanted to share it with readers of the blog. I placed this article under the label of biological spectroscopy, but I have no idea if spectroscopy is involved or not in the scanning employed by Bio-NEMS. It clearly is one more example where scanning technology is moving to solid-state. Very interesting advances in biological analysis.

http://bio-nems.com/
Bio-NEMS Corporation announced a strategic partnership and technology development agreement with In-Q-Tel (IQT) to accelerate commercialization of its rapid handheld DNA testing technology. IQT, based in Arlington, VA, is the independent strategic investment firm that identifies, adapts, and delivers technologies that support the missions of the U.S. Intelligence Community.
Bio-NEMS has developed proprietary, interdisciplinary innovations to enable DNA to be directly analyzed on the surface of a semiconductor device. This breakthrough capability is expected to enable DNA analysis in 5 minutes or less from a battery-powered device that can be operated by almost anyone.
“Our semiconductor-based approach enables low cost, digital accurate analysis for even the most challenging DNA/RNA applications such as human identification, oncology, non-invasive prenatal diagnostics and epigenetics,” says David Medin, CEO. “This technology has the potential to revolutionize law enforcement, security and medical diagnostics. The In-Q-Tel investment will help us to accelerate the commercialization of this much needed technology.”
“The semiconductor-based technology being developed by Bio-NEMS represents a step forward in the field of DNA and RNA analysis,” said Syd Ulvick, Senior Vice President in charge of Physical and Biological Technologies at IQT. “IQT is excited to help facilitate its continued development for both the commercial and government markets.”
About Bio-NEMS
Bio-NEMS is an emerging technology company based in Menlo Park, CA. The company has proprietary, interdisciplinary innovations to enable DNA to be directly analyzed on the surface of a high-speed, custom semiconductor device. The DNA sequencing market achieved a 1000-fold decrease in cost and analysis time by replacing electrophoresis-based analysis with semiconductor-based analysis. Bio-NEMS is expected to be the first company to use semiconductor-based analysis to drive DNA testing into the portable realm. For more information visit www.bio-nems.com

Abstract-Metallic mesh-based terahertz biosensing of single- and double-stranded DNA

Takayuki Hasebe¹, Shunsuke Kawabe¹, Hiroaki Matsui^1,2, and Hitoshi Tabata^1,2

¹Department of Bioengineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
²Department of Electrical Engineering and Information Systems, University of Tokyo, 

We report on a promising approach for the label-free analysis of DNA molecules with electromagnetic surface waves in the terahertz (THz) region. A metallic mesh with a polyvinylidene difluoride membrane is employed for THz transmission analysis. The metallic mesh with opening holes provides a sharp dip structure in a THz transmission spectrum, which is sensitive to a small change of the refractive index of a sample on the metallic mesh surface. The optical properties of a small amount of DNA molecules cannot be investigated by a free-space THz measurement because of the low absorption coefficients of such samples. However, metallic mesh-based THz measurement revealed the difference in optical properties between single- and double-stranded DNA molecules on the basis of refractive index, as estimated from a dip frequency shift of the metallic mesh. Therefore, our metallic-based THz technique provides a dramatically enhanced sensitivity, and demonstrates the potential of our approach of the analysis of biologically relevant DNA samples