 |
|
Sensitive laser instrument could aid search for life on Mars
October 16, 2008IDAHO FALLS -- Minuscule traces of cells can be detected in a mineral likely present on Mars, a new study shows. The results, obtained using a technique developed at the U.S. Department of Energy's Idaho National Laboratory, could help mission scientists choose Martian surface samples with the most promise for yielding signs of life.
INL's instrument blasts off tiny bits of mineral and looks for chemical signatures of molecules commonly found in cells. While other methods require extensive sample handling, this analysis relies on a "point-and-shoot" laser technique that preserves more of the rock and reduces contamination risk. In the current online issue of the peer-reviewed Geomicrobiology Journal, the researchers report they could detect biomolecules at concentrations as low as 3 parts per trillion.
High sensitivity is crucial for NASA's search for life on Mars, says INL scientist Jill Scott, whose team collaborated with researchers at the University of Montana-Missoula on the study.
"The worst-case scenario is a false negative," Scott says. "If you're just missing stuff, that would be devastating."
While other techniques also have achieved parts-per-trillion sensitivity, they often require scientists to first extract the organic cell remnants from the mineral. This type of preparation can use up large amounts of sample and potentially introduce contamination.
INL's method is based on a technique called laser desorption mass spectroscopy. By focusing a laser beam on a spot less than one-hundredth the width of a pencil point, the researchers can knock microscopic fragments off the mineral. Those fragments react with organic molecules to form detectable charged particles called ions. The team can then study the ion patterns for signatures that might be specific to biomolecules.
Typically, this method would require the organic molecules to be embedded in a synthetic matrix that encourages ion formation. But the INL team simply relies on the rock to act as the matrix, eliminating the need for sample preparation.
"We thought, what can the rock do for you?" Scott says. "You don't want to damage the sample more than you have to. You'd like to just shoot it directly."
With funding from NASA's Astrobiology program, the researchers have done previous studies showing that minerals like halite and jarosite yield distinct ion patterns when organic molecules are present. This time, they tried thenardite, a compound thought to be part of the Martian surface. Because thenardite is left behind when lakes dry up, its presence could signify the past existence of water -- and hence life.
The team tested thenardite samples taken from the evaporated Searles Lake bed in California. They also created artificial thenardite samples that contained traces of stearic acid, which is left behind by dead cells, and glycine, the simplest amino acid used by organisms on Earth. In all cases, the researchers found a distinct ion pattern that did not appear for thenardite alone, suggesting they had detected a signature for the biomolecules.
The team also measured the sensitivity of its instrument for the first time. By testing more and more dilute artificial samples, they found they could detect the stearic acid signature at levels as low as 3 parts per trillion. In fact, the signatures became even more distinct as concentration dropped, presumably because more ion-producing matrix surrounded each biomolecule.
While the instrument is too big to send into space, it could potentially be used for analysis if NASA brings Martian samples back to Earth. The INL study also could help determine which samples should be collected, based on how likely they are to show signs of life. Thenardite and jarosite look the most promising, Scott says, while hematite -- an iron-based compound common on the Martian surface -- has yielded poor results so far.
"The wider the variety of minerals we test, the larger the suite we can target on Mars," says collaborator Nancy Hinman, a geochemist at the University of Montana-Missoula.
The team's next step is to improve the laser on its machine. Right now, the instrument is ionizing only about 10 percent of the available biomolecules in the sample. If the remaining biomolecules could be ionized with a better laser, Scott says, the detection level could increase tenfold.
DOE/Idaho National Laboratory
"The worst-case scenario is a false negative," Scott says. "If you're just missing stuff, that would be devastating."
While other techniques also have achieved parts-per-trillion sensitivity, they often require scientists to first extract the organic cell remnants from the mineral. This type of preparation can use up large amounts of sample and potentially introduce contamination.
INL's method is based on a technique called laser desorption mass spectroscopy. By focusing a laser beam on a spot less than one-hundredth the width of a pencil point, the researchers can knock microscopic fragments off the mineral. Those fragments react with organic molecules to form detectable charged particles called ions. The team can then study the ion patterns for signatures that might be specific to biomolecules.
Typically, this method would require the organic molecules to be embedded in a synthetic matrix that encourages ion formation. But the INL team simply relies on the rock to act as the matrix, eliminating the need for sample preparation.
"We thought, what can the rock do for you?" Scott says. "You don't want to damage the sample more than you have to. You'd like to just shoot it directly."
With funding from NASA's Astrobiology program, the researchers have done previous studies showing that minerals like halite and jarosite yield distinct ion patterns when organic molecules are present. This time, they tried thenardite, a compound thought to be part of the Martian surface. Because thenardite is left behind when lakes dry up, its presence could signify the past existence of water -- and hence life.
The team tested thenardite samples taken from the evaporated Searles Lake bed in California. They also created artificial thenardite samples that contained traces of stearic acid, which is left behind by dead cells, and glycine, the simplest amino acid used by organisms on Earth. In all cases, the researchers found a distinct ion pattern that did not appear for thenardite alone, suggesting they had detected a signature for the biomolecules.
The team also measured the sensitivity of its instrument for the first time. By testing more and more dilute artificial samples, they found they could detect the stearic acid signature at levels as low as 3 parts per trillion. In fact, the signatures became even more distinct as concentration dropped, presumably because more ion-producing matrix surrounded each biomolecule.
While the instrument is too big to send into space, it could potentially be used for analysis if NASA brings Martian samples back to Earth. The INL study also could help determine which samples should be collected, based on how likely they are to show signs of life. Thenardite and jarosite look the most promising, Scott says, while hematite -- an iron-based compound common on the Martian surface -- has yielded poor results so far.
"The wider the variety of minerals we test, the larger the suite we can target on Mars," says collaborator Nancy Hinman, a geochemist at the University of Montana-Missoula.
The team's next step is to improve the laser on its machine. Right now, the instrument is ionizing only about 10 percent of the available biomolecules in the sample. If the remaining biomolecules could be ionized with a better laser, Scott says, the detection level could increase tenfold.
DOE/Idaho National Laboratory
Biomolecules Current Events and Biomolecules News RSSNew explanation for nature's hardiest life form
Got food poisoning? The cause might be bacterial spores, en extremely hardy survival form of bacteria, a nightmare for health care and the food industry and an enigma for scientists.
Tiny injector to speed development of new, safer, cheaper drugs
It's no bigger than a stamp packet but it has the potential to allow rapid development of a new generation of drugs and genetic engineering organisms, and to better control in-vitro fertilization.
Seeing previously invisible molecules for the first time
A team of Harvard chemists led by X. Sunney Xie has developed a new microscopic technique for seeing, in color, molecules with undetectable fluorescence.
Smallest Nanoantennas for High-speed Data Networks
More than 120 years after the discovery of the electromagnetic character of radio waves by Heinrich Hertz, wireless data transmission dominates information technology.
Herbal tonic for radiotherapy
Antioxidant extracts of the leaves of the Gingko biloba tree may protect cells from radiation damage, according to a study published in the International Journal of Low Radiation.
U of T researchers create microchip that can detect type and severity of cancer
U of T researchers have used nanomaterials to develop a microchip sensitive enough to quickly determine the type and severity of a patient's cancer so that the disease can be detected earlier for more effective treatment.
Capping a two-faced particle gives duke engineers complete control
Scientists drew fittingly from Roman mythology when they named a unique class of miniscule particles after the god Janus, who is usually depicted as having two faces looking in opposite directions.
Nonstick and laser-safe gold aids laser trapping of biomolecules
Biophysicists long for an ideal material-something more structured and less sticky than a standard glass surface-to anchor and position individual biomolecules.
Plant Microbe Shares Features with Drug-Resistant Pathogen
An international team of scientists has discovered extensive similarities between a strain of bacteria commonly associated with plants and one increasingly linked to opportunistic infections in hospital patients.
Nanocrystals Reveal Activity Within Cells
Researchers at the U.S. Department of Energy's (DOE) Lawrence Berkeley National Laboratory have created bright, stable and bio-friendly nanocrystals that act as individual investigators of activity within a cell.
More Biomolecules Current Events and Biomolecules News Articles
 |
Water and Biomolecules: Physical Chemistry of Life Phenomena (Biological and Medical Physics, Biomedical Engineering) by Kunihiro Kuwajima (Author), Kunihiro Kuwajima (Editor), Yuji Goto (Editor), Fumio Hirata (Editor), Masahide Terazima (Editor), Mikio Kataoka (Editor) Life is produced by the interplay of water and biomolecules. This book deals with the physicochemical aspects of such life phenomena produced by water and biomolecules, and addresses topics including "Protein Dynamics and Functions", "Protein and DNA Folding", and "Protein Amyloidosis". All sections have been written by internationally recognized front-line researchers. The idea for this book was born at the 5th International Symposium "Water and Biomolecules", held in Nara city, Japan, in 2008. |
 |
Heavy Metal Stress in Plants: From Biomolecules to Ecosystems by M.N.V. Prasad (Editor) Heavy metal phytotoxicity has been known for more than a century. Therefore, it is astonishing that interest in the effects of heavy metals on organisms has been aroused only recently. Research in the past years, however, has confirmed the immense damage by metal pollution to plants, the soil and ultimately to humans. This completely updated and enlarged second edition gives a state-of-the art review on both field and laboratory work. It deals with the various functional and ecological aspects of heavy metal stress on plants and outlines the scope for future research and the possibilities for remediation. |
 |
Modern Biophysical Chemistry: Detection and Analysis of Biomolecules by Peter Jomo Walla (Author) The only introductory text to address contemporary methods, the really interesting stuff to spice up a standard biophysics course is to be found here. Accessible and didactically written, it is based on a graduate course taught by the author for several years. By presenting a mix of basic theory and real life application examples, he successfully bridges the gap between theory and experiment. Divided into two major parts, this advanced textbook explains all relevant methods used in current industrial research. The first part, basic biophysical chemistry, surveys basic spectroscopic techniques and properties that are the prerequisite for the more sophisticated technologies discussed in the remainder of the book. The second part covers modern, cutting-edge bioanalytical techniques... |
 |
Peptide Nucleic Acids, Morpholinos and Related Antisense Biomolecules (Medical Intelligence Unit) by Christopher G. Janson (Author), Matthew J. During (Author) This volume is unique to the existing literature in the Peptide Nucleic Acid field, in that it focuses on comparing and contrasting PNA with other available oligonucleotide homologues and considers areas in which these biomolecules could be profitably applied to clinical and diagnostic applications. Part I of the book addresses comparative strengths and weaknesses of various nucleoside homologues. Part II of the book addresses specific translational or clinical applications for PNA and related antisense biomolecules. The editors have succeeded in presenting a balanced yet broad view of the methods available for gene targeting and modification. |
|
A Laboratory Guide to Biotin-Labeling in Biomolecule Analysis (Biomethods) by T. Meier (Editor), F. Fahrenholz (Editor) This book summarizes protocols and applications of recently developed or improved non-radioactive biotin-labelling techniques for proteins, glycoproteins and nucleic acids and will provide valuable help to researchers both in fundamental and in applied sciences. The first chapter of this volume compares the chemical properties of biotin-labelling compounds currently available and outlines their reactions principles. The following contributions provides a step-by-step protocol on how to prepare and successfully apply biotin-labelled probes for the analysis of complex biochemical and cellular systems. An extended troubleshooting section completes each of the protocols. In most cases these core protocols provide a guideline that encourage modifications according to the researchers'... | |
 |
Chemistry of Biomolecules: An Introduction by Richard J. Simmonds (Author) The aim of this textbook is to provide advanced undergraduates and postgraduates with information on the chemistry of biomolecules. In addition to descriptions of their syntheses and chemical properties, it explains how events at the molecular level create biological properties. The book covers the chemistry of those groups of compounds of biological importance which are included in undergraduate courses, such as carbohydrates, proteins, nucleic acids and steroids, plus two areas of pharmaceutical interest - prostaglandins and beta-lactam antibiotics. No previous knowledge of biology is assumed. |
 |
Solvation Effects on Molecules and Biomolecules: Computational Methods and Applications (Challenges and Advances in Computational Chemistry and Physics) by Sylvio Canuto (Editor) This volume is an interdisciplinary treatise on the theoretical approach to solvation problems. Solvents are important in chemistry, physics, and biology. Almost all experiments made in organic chemistry, including all kinds of spectroscopy, are made in solution. In biology, several reactions are known that only occur in an aqueous environment. In physics, the interaction with the environment changes optical properties and affects the design of sensors and devices. In recent years the development of theoretical methods to treat solvation problems has seen great progress and quantum chemistry is now making an important incursion into the liquid phase, coupling statistical physics with quantum mechanics. This book describes the essential details of the theoretical methods and... |
 |
Biochemistry, Biomolecules, Solutions Manual(for chapters 1-29 only) (Volume 1) by Donald J. Voet (Author), Judith G. Voet (Author) Biochemistry is a modern classic that had been thoroughly revised. Explains biochemical concepts while offering a unified presentation of life and its variation through evolution. Incorporates both classical and current research to illustrate the historical source of much of our biochemical knowledge. This new edition will be available in two volumes as well as one complete text. Volume 1 will cover Chapters 1-29. Volume 2 will repeat chapter 29 and will also include Chapters 30-35. |
 |
Mass Spectrometry in Biophysics : Conformation and Dynamics of Biomolecules by Igor A. Kaltashov (Author), Stephen J. Eyles (Author) The first systematic summary of biophysical mass spectrometry techniques Recent advances in mass spectrometry (MS) have pushed the frontiers of analytical chemistry into the biophysical laboratory. As a result, the biophysical community's acceptance of MS-based methods, used to study protein higher-order structure and dynamics, has accelerated the expansion of biophysical MS. Despite this growing trend, until now no single text has presented the full array of MS-based experimental techniques and strategies for biophysics. Mass Spectrometry in Biophysics expertly closes this gap in the literature. Covering the theoretical background and technical aspects of each method, this much-needed reference offers an unparalleled overview of the current... |
 |
Energy Landscapes: Applications to Clusters, Biomolecules and Glasses (Cambridge Molecular Science) by David Wales (Author) Many research groups are now attempting to understand how the properties of systems ranging from small molecules to proteins and glasses are determined by the energy landscape. This book provides a self-contained account of energy landscape theory and how it is applied in studies of clusters, biomolecules and glasses. Beautifully illustrated in full color, the volume is geared to graduate students as well as professionals. |
| © 2009 BrightSurf.com |