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Ion Microscopy In Biology, George H. Morrison, Isabelle Gay, Subhash Chandra Jan 1994

Ion Microscopy In Biology, George H. Morrison, Isabelle Gay, Subhash Chandra

Scanning Microscopy

Ion microscopy, a mass spectrometry based isotopic imaging technique, is uniquely suited for ion transport-related problems in biological systems. Due to its high sensitivity, it can image the transport and distribution of both major and minor elements (isotopes) at subcellular resolutions. The images of major elements such as K, Na, Cl, etc., can be viewed directly and recorded in real-time from the microchannel plate-fluorescent screen detector of the instrument. The low concentration physiologically important elements, such as Ca, need about one minute of integration for good quality imaging. The isotopic imaging capability of ion microscopy provides a unique approach for …


Use Of Pyocin To Select A Haemophilus Ducreyi Variant Defective In Lipooligosaccharide Biosynthesis, A A. Campagnari, R Karalus, M A. Apicella, William Melaugh, A J. Lesse, B W. Gibson Jan 1994

Use Of Pyocin To Select A Haemophilus Ducreyi Variant Defective In Lipooligosaccharide Biosynthesis, A A. Campagnari, R Karalus, M A. Apicella, William Melaugh, A J. Lesse, B W. Gibson

Chemistry Faculty Publications

Haemophilus ducreyi, a cause of genital ulcer disease in developing countries, appears to facilitate the heterosexual transmission of the human immunodeficiency virus in Africa. Despite an increase in studies of this gram-negative human pathogen, little is known about the pathogenesis of chancroid. Our studies have shown that the lipooligosaccharides (LOS) of H. ducreyi may play an important role in ulcer formation. Monoclonal antibody and mass spectrometric analyses identified a terminal trisaccharide present on H. ducreyi LOS that is immunochemically similar to human paragloboside. This epitope is present on the LOS of Neisseria gonorrhoeae, and it may be the site of …


Utilization Of Wood Duck Nest Boxes With Respect To Plant Community Type, Orientation And Juxtaposition At The Green Bottom Wildlife Management Area, West Virginia, Anthony Benjamin Borda Jr. Jan 1994

Utilization Of Wood Duck Nest Boxes With Respect To Plant Community Type, Orientation And Juxtaposition At The Green Bottom Wildlife Management Area, West Virginia, Anthony Benjamin Borda Jr.

Theses, Dissertations and Capstones

Utilization of wood duck (Aix sponsa, L.) nest boxes was evaluated at the Green Bottom Wildlife Management Area, a 1,110-acre mid-Ohio Valley floodplain. Primary focus was directed upon nest box utilization by the wood duck but use by other wildlife was observed and recorded. Utilization of the nest boxes by the wood duck was analyzed with respect to plant community type, orientation and juxtaposition to other wood duck nest boxes. Forty-three wood duck next boxes were observed and inspected in 1993. Wood ducks nested in 24 of the nest boxes, and 361 eggs were found. Clutch size ranged …


Study On The Neural Cell Adhesion Molecules In Heart Development Of Chicken, Mee Kyeong Byeon Jan 1994

Study On The Neural Cell Adhesion Molecules In Heart Development Of Chicken, Mee Kyeong Byeon

MUSC Theses and Dissertations

Cell adhesion molecules mediate specific cell-cell interactions during embryogenesis and tissue formation. Among cell-cell adhesion molecules (CAMs), we have been particularly interested in the neural cell adhesion molecule (NCAM) which is the prototypical member of the family of Ca++ -independent CAMs. Previous studies of NCAM cDNAs have revealed an alternatively spliced set of small exons (12A, 12B, 12C, 12D) that encode a region in the extracellular portion of the molecule known as the muscle specific domain (MSD). The entire MSD region can be expressed in skeletal muscle, heart, and skin; only exons 12A and 12D have been found in brain. …


Patterns Among Host Plants Of Potato Leafhopper, Empoasca Fabae (Homoptera: Cicadellidae), William O. Lamp, Gary R. Nielsen, Stephen D. Danielson Jan 1994

Patterns Among Host Plants Of Potato Leafhopper, Empoasca Fabae (Homoptera: Cicadellidae), William O. Lamp, Gary R. Nielsen, Stephen D. Danielson

Department of Entomology: Faculty Publications

Ecological characteristics of potato leafhopper, Empoasca fabae (Harris), including polyphagy, suggest that non-economic plant species in the landscape may be important to its population ecology. The objectives of this study were to compile a host list, to ascertain taxonomic and ecological patterns within the list, and to determine host utilization in non-crop habitats. The host plant list included 220 species in 100 genera and 26 families. Fabaceae represented 47% of the genera and 62% of the species. Yet, the list includes a diversity of taxonomic groups within the class Magnoliopsida, representing highly divergent chemistry and morphological types. Ecological classifications, based …


Historic Trends In The Secchi Disk Transparency Of Lake Pontchartrain, J.C. Francis, M.A. Poirrier, D.E. Barbe, V. Wijesundera, M.M. Mulino Jan 1994

Historic Trends In The Secchi Disk Transparency Of Lake Pontchartrain, J.C. Francis, M.A. Poirrier, D.E. Barbe, V. Wijesundera, M.M. Mulino

Gulf and Caribbean Research

A major environmental concern about Lake Pontchartrain is an assumed long-term increase in turbidity based on Secchi disk transparency observations. Regression of the available data on Secchi disk transparency versus time (1953 through 1990) reveals a statistically significant decrease in transparency of about 40%. However, the data set is biased in that it does not adequately represent the seasonal effects of salinity and wind speed. Two analytical procedures were undertaken to determine the extent to which the apparent long-term decrease in transparency was dependent on the seasonal bias. One procedure involved seasonal adjustment of the data for the effects of …


Research : Co-Operation Is The New Style, John Hamblin, Ian Maling Jan 1994

Research : Co-Operation Is The New Style, John Hamblin, Ian Maling

Journal of the Department of Agriculture, Western Australia, Series 4

Co-operative Research Centres, or CRCs as they are known, are a new trend in agricultural research. Instead of organisations such as Departments of Agriculture or universities pursuing their own individual research projects, sometimes in competition or covering similar fields, the idea is to combine talents and expertise. CRCs were a Federal Government initiative launched in 1990, and the Centre for Legumes in Mediterranean Agriculture was the first involving agriculture in Western Australia.


Introduction: One Hundred Years Of Natural History In Turkmenistan, Victor Fet Jan 1994

Introduction: One Hundred Years Of Natural History In Turkmenistan, Victor Fet

Biological Sciences Faculty Research

As part of the famous “Great Game” between the Russian and British Empires in Central Asia, Turkmenistan was the last colonial prize of the Russian tsars; its delineation from Afghanistan was completed only in the 1890s. The Russian Empire’s Transcaspian Region (Zakaspiiskaya Oblast) was roughly what Turkmenistan is today; its neighbors were the semi-independent emirate of Bokhara to the east and khanate of Khiva to the north, both remnants of medieval Muslim empires.

This book combines the results of basic scientific research in biogeography and ecology; its purpose is to give a fairly comprehensive account of the nature of Turkmenistan. …


Models To Predict Yield Loss Due To Weeds In Rice Ecosystems, John L. Lindquist Jan 1994

Models To Predict Yield Loss Due To Weeds In Rice Ecosystems, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Yield loss models have been developed and evaluated for irrigated rice ecosystems with respect to effects of Echinochloa crusgalli. Simple regression models that give the relation between yield loss and weed density or relative leaf area are discussed with respect to their practical value in weed management in rice. More complex eco-physiological process models have been developed and used for rice ecosystems as well. Such models can be useful as a tool in research, whereas more simple approaches are needed for practical application in weed management.


Chesapeake Bay Phytoplankton: I. Composition, Harold G. Marshall Jan 1994

Chesapeake Bay Phytoplankton: I. Composition, Harold G. Marshall

Biological Sciences Faculty Publications

A list of 708 Phytoplankton taxa from 10 algal divisions has been compiled for the Chesapeake Bay and is based on the analysis of 2384 water samples over three decades of study.


Preface To Biology Of The Heteromyidae, Hugh H. Genoways, James H. Brown Aug 1993

Preface To Biology Of The Heteromyidae, Hugh H. Genoways, James H. Brown

University of Nebraska State Museum: Mammalogy Papers

What is the family Heteromyidae? It is the group ofexclusively New World rodents that includes the kangaroo rats, pocket mice, and kangaroo mice ofthe desert, grasslands, and shrublands of western North America as well as the spiny and pouched rats of the subtropical shrublands and tropical deciduous and evergreen forests of North America, Central America, and northernmost South America. It is a large family, with six genera and 316 species.


Extending The Symbiotype Concept To Host Voucher Specimens, Daniel R. Brooks Aug 1993

Extending The Symbiotype Concept To Host Voucher Specimens, Daniel R. Brooks

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Recently, Frey, Yates, Duszynski, Gannon, and Gardner (1992) suggested that parasitologists deposit specimens of hosts from which type specimens of new parasite species are collected. Their proposal was directed especially at systematic and evolutionary biologists. Frey et al. (1992) pointed out that, whether one emphasizes microevolutionary (e.g., Price, 1980) or macroevolutionary (e.g., Brooks and Mc- Lennan, 1993) aspects of parasite evolutionary biology, much of the context of evolution involves hosts. Robust estimates of the selective effects and the patterns of diversification of host associations require the best possible estimates of the host species involved. This is …


The Isolation And Identification Of Polyphenolics From Grape Seeds And Their Activity Towards Specific Cell Lines, Joseph A. Reddy Jul 1993

The Isolation And Identification Of Polyphenolics From Grape Seeds And Their Activity Towards Specific Cell Lines, Joseph A. Reddy

Chemistry & Biochemistry Theses & Dissertations

Grape seed extract is being marketed in France for cardiovascular use and skin care. The active constituents of both these drugs are certain polyphenols called procyanidins. A similar seed extract has now been obtained from Virginia Chardonnay grape seeds. Ten of the major components in this extract have been isolated in their pure form by the semi-preparative HPLC separation on a YMC ODS-AQ (Octadecylsilane-AQ) column. The ODS-Aq column has been shown to have a better resolving capacity compared to the Spherisorb ODS (Octadecylsilane) column previously described in the literature. This has been attributed to the ODSAQ support which has both …


Modelling Avian Distributions Of The Navarrese Region In Northern Spain With A Geographic Information System, Samuel Soret-Garcia Jun 1993

Modelling Avian Distributions Of The Navarrese Region In Northern Spain With A Geographic Information System, Samuel Soret-Garcia

Loma Linda University Electronic Theses, Dissertations & Projects

GIS (Geographic information Systems) technology was used for identifying relations between environmental characteristics and the breeding distributions of nine avian species of the Navarrese region in northern Spain. Data overlays of multiple GIS layers derived the explanatory variables for modelling the breeding distributions from logistic regressions. A spatial autocorrelation analysis was conducted to characterize the distribution patterns and to incorporate spatial factors (neighborhood effects) into their analysis.

All nine patterns analyzed exhibited a high level of spatial autocorrelation. Accordingly, the basic hypothesis of spatial randomness was rejected in favor of spatial clustering for the sample data. The breeding distributions strongly …


Mechanisms Of Hard-To-Cook Defect In Cowpeas: Verification Via Microstructure Examination, Keshun Liu, Yen-Con Hung, R. Dixon Phillips Jan 1993

Mechanisms Of Hard-To-Cook Defect In Cowpeas: Verification Via Microstructure Examination, Keshun Liu, Yen-Con Hung, R. Dixon Phillips

Food Structure

It has been hypothesized that part of the hard-to-cook (HTC) defect in cowpeas is due to decreases in solubility and thermal stability of intracellular proteins during storage since coagulated proteins would limit water to starch and prevent full swelling during cooking. To verify this hypothesis, effects of soaking and heating temperature on texture, water absorption, protein water extractability and microstructure of control and HTC cowpea seeds (aged or treated) were studied. Scanning electron microscopy showed no structural difference between dry control and dry aged seeds. However, after soaking, in contrast to the control, aged seeds exhibited a coarse protein matrix …


Phytoplankton Relationships To Water Quality In Lake Drummond And Two Drainage Ditches, Christine G. Phillips, Harold G. Marshall Jan 1993

Phytoplankton Relationships To Water Quality In Lake Drummond And Two Drainage Ditches, Christine G. Phillips, Harold G. Marshall

Biological Sciences Faculty Publications

A twelve-month phytoplankton study was conducted in Lake Drummond and Washington and Jericho Ditches from December 1988 to November 1989. Four dominant phytoplankton groups were identified at these sites. These were the Bacillariophyceae, Cyanophyceae, Cryptophyceae and an autotrophic picoplankton component. Over the past 20 years there has been a decrease in the mean pH levels of Lake Drummond and the replacement of one its former major components, the Chlorophyceae, by the Cyanophyceae. Based on water quality analysis results and species diversity indices, Lake Drummond is classified as in an early eutrophic stage of development.


Handbook Of Field Methods For Monitoring Landbirds, C. John Ralph, Geoffrey R. Geupel, Peter Pyle, Thomas E. Martin, David F. Desante Jan 1993

Handbook Of Field Methods For Monitoring Landbirds, C. John Ralph, Geoffrey R. Geupel, Peter Pyle, Thomas E. Martin, David F. Desante

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

This handbook is a compilation of methods that can be used to assay population size, demographics, and status of many species of birds occurring in a wide variety of habitats. The handbook will prove useful to field biologists, managers, and scientists anywhere in the New World from the arctic through the tropics. The methods include four types of censuses for determining population size and trends, mist-netting and nest searches to determine demographic parameters, and other methods that will be useful in operating a monitoring station, including habitat and weather observations, and suggestions for training personnel and possibilities for detailed studies. …


The Expression Pattern Of The Tonoplast Intrinsic Protein Γ-Tip In Arabidopsis Thaliana Is Correlated With Cell Enlargement, Edward Himelblau, Herman Hofte, Dolors Ludevid, Maarten J. Chrispeels Dec 1992

The Expression Pattern Of The Tonoplast Intrinsic Protein Γ-Tip In Arabidopsis Thaliana Is Correlated With Cell Enlargement, Edward Himelblau, Herman Hofte, Dolors Ludevid, Maarten J. Chrispeels

Biological Sciences

The vacuolar membrane (tonoplast) contains an abundant intrinsic protein with six membrane-spanning domains that is encoded by a small gene family. Different isoforms of tonoplast intrinsic protein (TIP) are expressed in different tissues or as a result of specific signals. Using promoter-β-glucuronidase (GUS) fusions and in situ hybridization, we have examined the expression of γ-TIP in Arabidopsis thaliana. GUS staining of plants transformed with promoter-GUS fusions showed that γ-TIP gene expression is high in recently formed tissues of young roots. In the shoot, γ-TIP gene expression was highest in the vascular bundles of stems and petioles, as well as …


Remote Detection Of Coral 'Bleaching' Using Pulsed-Laser Fluorescence Spectroscopy, J. T. Hardy, F. E. Hoge, J. K. Yungel, Richard E. Dodge Nov 1992

Remote Detection Of Coral 'Bleaching' Using Pulsed-Laser Fluorescence Spectroscopy, J. T. Hardy, F. E. Hoge, J. K. Yungel, Richard E. Dodge

Marine & Environmental Sciences Faculty Articles

Despite their biological and economic importance coral reefs are increasingly threatened by human activities. Recently, 'bleaching' of reefs, i.e. loss of photosynthetic pigmentation, has occurred at numerous globally-distributed sites. A number of environmental stressors, including increased water temperature, can induce bleaching. Several investigators have suggested that the widespread occurrence of coral bleaching represents an early warning signal of global greenhouse warming. Regardless of the cause, the extent of coral bleaching, both regionally and globally, needs to be documented and monitored. We conducted laboratory studies to evaluate the potential of using remotely-sensed laser-induced fluorescence to monitor coral pigmentation. Five species of …


Molecular Genetic Mapping Of The Multiple Endocrine Neoplasia Type 1 Locus, Joanna T. Pang, Mark A. Pook, James H. Eubanks, Carol Jones, Veronica Van Heyningen, Glen A. Evans, Rajesh V. Thakker Sep 1992

Molecular Genetic Mapping Of The Multiple Endocrine Neoplasia Type 1 Locus, Joanna T. Pang, Mark A. Pook, James H. Eubanks, Carol Jones, Veronica Van Heyningen, Glen A. Evans, Rajesh V. Thakker

Henry Ford Hospital Medical Journal

Familial multiple endocrine neoplasia type 1 (MEN 1) is an autosomal dominant disorder characterized by the combined occurrence of tumors of the parathyroid glands, the endocrine pancreas, and the pituitary gland. MEN 1 tumors have previously been shown to be associated with the loss of alleles on chromosome 11, and deletion mapping studies together with family linkage studies have localized the MEN 1 gene to 11q13. A detailed genetic map around the MEN 1 locus is required to facilitate further characterization and cloning of the gene (MEN1). We have characterized a panel of seven rodent-human somatic cell hybrids which contain …


South American Oxybelus I. Notes On Types Of Spinola, F. Smith, Brethes, Pate, And Schrottky (Hymenoptera, Sphecidae, Crabroninae), Richard M. Bohart Sep 1992

South American Oxybelus I. Notes On Types Of Spinola, F. Smith, Brethes, Pate, And Schrottky (Hymenoptera, Sphecidae, Crabroninae), Richard M. Bohart

Insecta Mundi

The names of previously described South American species of Oxybelus are listed, annotated, and synonymy given. Nomenclature changes are: brethesi is a new name for interruptus Brethes 1913; decipiens Brethes 1913 and pamparum Brethes 1913 are synonyms of catamarcensis Schmttky 1909; fritzi is a new name for modestus Brethes 1913; agnitus Brethes 1913 is a synonym of marginatus F. Smith 1866; joergenseni Brethes 1913 is a synonym of paraguayensis Brethes 1909; and tarijensis Brethes 1913 is a synonym of platensis Brethes 1901. Neotypes are established for platensis and catamarcensis, and lectotypes for americanus, argentinus, modestus, marginatus, and tarijensis …


Parasiticidal Effect Of Chemotherapy In Alveolar Hydatid Disease: Review Of Experience With Mebendazole And Albendazole In Alaskan Eskimos, J. F. Wilson, Robert L. Rausch, B. J. Mcmahon, P. M. Schantz Aug 1992

Parasiticidal Effect Of Chemotherapy In Alveolar Hydatid Disease: Review Of Experience With Mebendazole And Albendazole In Alaskan Eskimos, J. F. Wilson, Robert L. Rausch, B. J. Mcmahon, P. M. Schantz

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Evidence that the larval stage of Echinococcus multilocularis in humans is killed by chemotherapy is presented in a review of our 17-year experience with treatment of alveolar hydatid disease in Alaska. The efficacy of chemotherapy was assessed with use of an in vivo assay of parasite viability by means of inoculation of voles, immunohistochemical tests, and histopathologic findings. Of 14 tests performed for nine patients, 12 in vivo assays (86%) were negative after chemotherapy, while only two (17%) of 12 vole tests for seven untreated patients were negative. Regression or arrest of growth of metastatic and primary hepatic lesions, together …


Effect Of Hindlimb Unweighting On Tissue Blood Flow In The Rat, Kerry S. Mcdonald, M. D. Delp, Robert H. Fitts Jun 1992

Effect Of Hindlimb Unweighting On Tissue Blood Flow In The Rat, Kerry S. Mcdonald, M. D. Delp, Robert H. Fitts

Biological Sciences Faculty Research and Publications

The purpose of this study was to characterize the distribution of blood flow in the rat during hindlimb unweighting (HU) and post-HU standing and exercise and examine whether the previously reported (Witzmann et al., J. Appl. Physiol. 54: 1242–1248, 1983) elevation in anaerobic metabolism observed with contractile activity in the atrophied soleus muscle was caused by a reduced hindlimb blood flow. After either 15 days of HU or cage control, blood flow was measured with radioactive microspheres during unweighting, normal standing, and running on a treadmill (15 m/min). In another group of control and experimental animals, blood flow was measured …


A Review Of Graphite And Gold Surface Studies For Use As Substrates In Biological Scanning Tunneling Microscopy Studies, Carol R. Clemmer, Thomas P. Beebe Jr. Apr 1992

A Review Of Graphite And Gold Surface Studies For Use As Substrates In Biological Scanning Tunneling Microscopy Studies, Carol R. Clemmer, Thomas P. Beebe Jr.

Scanning Microscopy

The current status of biological Scanning Tunneling Microscopy (STM) investigations and the importance of using a well-characterized substrate are discussed. The findings of over two years of experiments and over 1,000 images obtained on gold substrates prepared by a variety of different methods are statistically summarized and compared to a very flat reference substrate, highly oriented pyrolytic graphite (HOPG). In an effort to begin to corroborate STM results with those obtained from other more established techniques, the results of Auger Electron Spectroscopy (AES) and Electron Spectroscopy for Chemical Analysis (ESCA) of biomolecular STM samples are presented.


Integrated Single Crystal Detector For Simultaneous Detection Of Cathodoluminescence And Backscattered Electrons In Scanning Electron Microscopy, Rudolf Autrata, Josef Jirák, Jiří Špinka, Otakar Hutař Jan 1992

Integrated Single Crystal Detector For Simultaneous Detection Of Cathodoluminescence And Backscattered Electrons In Scanning Electron Microscopy, Rudolf Autrata, Josef Jirák, Jiří Špinka, Otakar Hutař

Scanning Microscopy

The design of the majority of the available high efficiency cathodoluminescence (CL) detection systems allows the secondary electron (SE) and backscattered electron (BSE) image modes to be detected simultaneously to a limited degree only. The described CL-BSE detector is based on the single crystal YAG scintillator shaped as a spherical mirror which reflects photons emitted from the CL specimen and focuses them on to the entrance surface of a fibre optic light guide connected to the photomultiplier tube (PMT I). The backscattered electrons emitted from the CL specimen move through the reflecting layer of the mirror into the YAG scintillator …


A Brief Introduction To Aims And Methods For Image Processing Of Electron Micrographs Of Biological Specimens, Murray Stewart Jan 1992

A Brief Introduction To Aims And Methods For Image Processing Of Electron Micrographs Of Biological Specimens, Murray Stewart

Scanning Microscopy

A common problem with electron micrographs of biological objects is that fine details are usually faint and, moreover, tend to be obscured by background noise from stain and support film. Filtering is a useful way to improve the signal-to-noise ratio and is particularly important when trying to detect small changes (conformational or due to labelling) or when examining frozen hydrated objects, where the statistical definition of the image has been reduced because of the low-dose conditions needed to prevent radiation damage. Filtering can also be used to address the superposition effects that result from the large depth of focus of …


Supplement To The 1987 Bibliography, Stephen L. Wood, Donald E. Bright Jr. Jan 1992

Supplement To The 1987 Bibliography, Stephen L. Wood, Donald E. Bright Jr.

Great Basin Naturalist Memoirs

No abstract provided.


Coprolite Analysis: A Biological Perspective On Archaeology, Karl J. Reinhard, Baughn M. Bryant Jr Jan 1992

Coprolite Analysis: A Biological Perspective On Archaeology, Karl J. Reinhard, Baughn M. Bryant Jr

Karl Reinhard Publications

The most remarkable dietary remains recoverable from archaeological contexts are coprolites. Coprolites are desiccated or mineralized feces that are preserved in sheltered and open sites in arid regions, primarily in the New World. These dietary remains are remarkable from several perspectives. They typically contain a variety of macroscopic and microscopic remains that form interrelated data sets for the reconstruction of diets. Because contexts containing coprolites are typified by excellent preservation, the remains coprolites contain tend to be in better states of preservation than dietary remains recovered from nonfecal deposits. Coprolites also contain the well-preserved remains of intestinal parasites and pathogens …


Microbeam Studies Of The Sensitivity Of Structures Within Living Cells, L. A. Braby Dec 1991

Microbeam Studies Of The Sensitivity Of Structures Within Living Cells, L. A. Braby

Scanning Microscopy

Determining the biological effects of low doses of radiation with high linear energy transfer (LET) is complicated by the stochastic nature of charged-particle interactions. Populations of cells exposed to very low radiation doses contain a few cells which have been hit by a charged particle, while the majority of the cells receive no radiation damage. At somewhat higher doses, a few cells receive two or more events. Because the effects of damage produced by separate events can interact in the cell, we have had to make assumptions about the nature of these interactions in order to interpret the results of …


A Review Of Scanning Tunneling Microscope And Atomic Force Microscope Imaging Of Large Biological Structures: Problems And Prospects, B. L. Blackford, M. H. Jericho, P. J. Mulhern Dec 1991

A Review Of Scanning Tunneling Microscope And Atomic Force Microscope Imaging Of Large Biological Structures: Problems And Prospects, B. L. Blackford, M. H. Jericho, P. J. Mulhern

Scanning Microscopy

The application of the scanning tunneling microscope (STM) and the atomic force microscope (AFM) to the study of small biological molecules, such as DNA and smaller molecules, has received considerable attention in the literature. This paper reviews STM and AFM studies of larger biological structures such as bacterial membranes, bacteriophages, viruses, antibodies, etc. The problems encountered in these applications are emphasized, with particular reference to the unknown conduction mechanism, tip-sample interaction forces, and tip-sample convolution artifacts in the images. The latter problem is illustrated by new results from IgG antibody complexes attached to a bacterial sheath layer. A new conduction …