Because of its superior resolution, short-wavelength light is used in life science and biology applications to study living cells down to the sub-cellular level. Specifically, deep ultraviolet (DUV) light is used in biological imaging and circular dichroism (CD) spectroscopy; soft x-ray light is used in water-window microscopy and microbeam studies on biological cells.

DUV Light in Life Sciences Applications

Circular Dichroism - Circular dichroism (CD) is a form of spectroscopy based on the differential absorption of right- and left-circularly polarized light. It can be used to determine the secondary structures of protein and DNA. As the need to determine the structure of larger and larger numbers of proteins grows, techniques that are complicated and time-consuming, such as NMR (nuclear magnetic resonance) spectroscopy and X-ray crystallography, cannot be efficiently performed. Therefore, quicker and less complex techniques for determining protein structure, like CD spectroscopy, will be required. Operating in the deep UV spectral region, the Energetiq EQ-1000 LDLS Laser-Driven Light Source can easily achieve the high brightness, high power UV light needed to perform CD spectroscopy.

Biological Imaging - The ability to see the structure of living organisms and to analyze the relationship between form and function is key to biological studies. However, living organisms are dynamic structures, and biological processes that occur over time such as protein changes, cell division, embryo development, or neural activity necessitate the visualization of structures in multi-dimensions. With the development of advanced biological imaging technology it is now possible to observe molecular and cellular interactions that underlie essential functions within living cells and tissues as they take place.

The Energetiq EQ-1000 LDLS Laser-Driven Light Source is an ideal tool to use for these particular studies due to the high resolution, power, and brightness of the UV light generated. By utilizing DUV light as the light source, the nanostructure of living cells and tissues can be directly observed with extremely high resolution, without the extreme purchasing and operating costs associated with the use of conventional lasers.

Soft X-Ray Light in Life Sciences Applications

Soft X-Ray Microscopy and Soft X-Ray Microbeams - Soft x-ray light for microbeam studies and microscopy can readily be found in national lab synchrotron facilities. However, this limits the availability of soft x-rays to those researchers who are able to obtain beam time and who are able to bring their experiments to the synchrotrons. With its novel plasma approach, Energetiq’s compact EQ-10SX Soft X-Ray Light Source enables soft x-ray microbeam and microscope experiments to be carried out in any typical biological research laboratory.

Microbeam studies of the effects of ionizing radiation on biological cells have long been performed using particle accelerators. The limitations of charged particle beams such as alpha particles include difficulty in focusing the beam to below one micrometer in diameter. Soft x-rays provide similar ionizing radiation effects on biological samples, but are readily focused to very small spot size using Fresnel zone-plate lenses. In principle, beams significantly less than 100nm in diameter can be produced using such optics. This allows the targeting of sub-cellular structures within cells with a controlled soft x-ray beam, to evaluate the response of such structures to ionizing radiation. Applications include the effects of environmental radiation, and the mechanisms of radiotherapy for cancer and the like.

In soft x-ray microscopy, images produced with soft (low energy) x-ray beams have 10 times the resolution of images obtained with the best visible light microscopes. In addition, studies can be done on living cells without destroying them. Soft x-ray microscopy can make a major contribution to the understanding of cell function and structure. The Energetiq EQ-10SX light source has been shown to produce sufficient 2.88nm light to allow production of high resolution images in a practical time.

Download the paper "A Novel, High-Brightness Electrodless Z-Pinch Soft X-Ray Source for Microbeam Applications," presented at the 7th International Workshop: Microbeam Probes of Cellular Radiation Response, Columbia University, New York, New York, March 2006.