Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
  • G01N33/543—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals
  • G01N33/551—Immunoassay; Biospecific binding assay; Materials therefor with an insoluble carrier for immobilising immunochemicals the carrier being inorganic
  • G01N33/553—Metal or metal coated
• • C—CHEMISTRY; METALLURGY
  • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
  • C12Q—MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
  • C12Q1/00—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
  • C12Q1/70—Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving virus or bacteriophage
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/53—Immunoassay; Biospecific binding assay; Materials therefor
  • G01N33/569—Immunoassay; Biospecific binding assay; Materials therefor for microorganisms, e.g. protozoa, bacteria, viruses
  • G01N33/56983—Viruses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B82—NANOTECHNOLOGY
  • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
  • B82Y35/00—Methods or apparatus for measurement or analysis of nanostructures
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2333/00—Assays involving biological materials from specific organisms or of a specific nature
  • G01N2333/005—Assays involving biological materials from specific organisms or of a specific nature from viruses
  • G01N2333/01—DNA viruses
  • G01N2333/065—Poxviridae, e.g. avipoxvirus
  • G01N2333/07—Vaccinia virus; Variola virus
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S977/00—Nanotechnology
  • Y10S977/84—Manufacture, treatment, or detection of nanostructure
  • Y10S977/849—Manufacture, treatment, or detection of nanostructure with scanning probe
  • Y10S977/852—Manufacture, treatment, or detection of nanostructure with scanning probe for detection of specific nanostructure sample or nanostructure-related property
  • Y10S977/853—Biological sample

Definitions

• the present invention relates to the detection and characterization of pathogens, viruses, and other biological materials.
• Pathogens constitute a critical problem for human, animal and plant health. Pathogens may cause infections that result in a variety of human illnesses and can lead to a large number of deaths. Such pathogens may include viruses, bacteria, prions, fungi, molds, eukaryotic microbes and parasites of many types. Moreover, pathogens infect agriculturally important plant and animal species, resulting in economic hardship. Detection and identification of pathogens in relevant materials (e.g., water, air, blood, tissues, organs, etc.) is essential to minimize the transfer and spread of infections. Furthermore, quick identification may aid in devising effective treatment strategies. [004] One class of pathogens is viruses. Viruses are used here as an example and not intended to limit the scope of the invention in any way. Viral infections extol a great morbidity and mortality among the human population.
• Infectivity-based assays are seldom used in diagnostics yet, both cell culture and animal-based amplification of virus in_a sample may be necessary for many of the current diagnostic procedures.
• the use of animals in infectivity assays is costly, time consuming and subject to ethical dispute.
• Serodiagnosis still exists in many hospitals principally because there are no good alternatives for some infections. Serology is largely performed to determine antibody levels and to estimate the probability for infection.
• Antibody based tests are popular, but are usually limited to a battery of individual tests in a macroscopic format (e.g., Enzyme Linked ImmunoSorbant Assay, or ELISA).
• Standard microbiological approaches to detect anthrax and other bacterial pathogens involve growth of the agent on nutrient agar and visual identification after various staining procedures. Carbon source utilization testing in various media identifies and differentiates among closely related isolates. Viral pathogens are usually identified after their administration, infection and amplification in animals, particularly embryonated eggs, mice or cell culture. This is the basic microbial identification scheme practiced today. While precise in their verification of pathogen identity, these procedures are very slow.
• PCR tests are extremely sensitive and are usually employed in cases where there is prior reason to suspect the presence of a particular pathogen, such as following a positive test for HIV antigens. PCR methods, however, are relatively costly and time consuming. Furthermore, PCR tests are of a relatively limited applicability because of the requirement of enzyme activity and because of the frequency of false positives.
• the invention described herein is an affinity capture substrate, or sensor, that can be read by an atomic force microscope (AFM) or another type of scanning probe microscope (SPM) for a simple, rapid, sensitive and high throughput method for detection of pathogens, biological materials, viruses, etc.
• AFM atomic force microscope
• SPM scanning probe microscope
• This method can be applied to detect the target material in a target sample, including whole viruses, viral proteins and viral nucleic acids as well as to distinguish between strains of similar pathogens and biomaterials. Additionally, fluorescence or other methods commonly practiced for detection of biological binding events can be employed when desired.
• a method of detecting a target pathogen comprising the steps of providing a substrate with a surface, depositing a patterned gold layer on the surface, depositing a deposition material on the surface, the deposition material capable of interacting with the target pathogen, and exposing the deposition material to a target sample which can contain the target pathogen and detecting resultant molecular interaction events between the deposition material and the target pathogen by imaging the surface with an atomic force microscope.
• An apparatus for the detection of a vaccinia virus comprising a gold layer deposited on a substrate, an C(x) alkane linker covalently attached to the gold layer, protein A/G tethered to the surface through the alkane linker, and anti-vaccinia antibody deposited on the surface in a domain such that a portion of the deposited antibody retains activity.
• a method of detecting a target pathogen comprising the steps of providing a substrate with a surface, depositing a deposition material on the surface, the deposition material capable of interacting with the target pathogen, exposing the deposition material to a target sample which can contain the target pathogen and detecting resultant molecular interaction events between the deposition material and a target pathogen.
• FIG. 1 is an illustration of the AFM detection method.
• FIG. 2a is a graphical representation of a chip with a deposition material thereon and an AFM scan of the same.
• FIG. 2b is a graphical representation of a chip_with a deposition material on the surface that has a target material attached and an AFM scan of the same.
• FIG. 3 is a graphical representation of a chip with two different deposition materials placed onto two different deposition domains.
• FIG. 4a is a graphical representation of a chip with a deposition material on the surface and a control surface before and after attachment of a target material.
• FIG. 4b is another graphical representation of the chip of FIG. 4a.
• FIG. 4c is a representation of an AFM scan of the chip of FIG. 4a.
• FIG. 5a illustrates the representative layers of a chip where a deposition material is attached by passive adsorption.
• FIG. 5b illustrates the representative layers of a chip where a deposition material is attached by active immobilization.
• FIG. 6a is a perspective view of a chip of the present invention with deposition material deposited thereon.
• FIG. 6b is a perspective view of a chip of the present invention after being exposed to a target sample containing a target material.
• FIG. 6c is a perspective view of the chip of FIG. 6b after washing.
• FIG. 7a is an AFM scan of a chip of the present invention after deposition of a deposition material.
• FIG. 7b is a scan of the chip of FIG. 7a after exposing the chip to a target material.
• FIG. 7c is a scan of a chip of the present invention after exposing the chip to a control.
• FIG. 8 is a graph of the number of target material particles bound to a chip surface versus exposure time for various concentrations of target material.
• pathogen is used to mean any sort of viral, bacterial, fungal, prion, microbial or other material that can be detected using the teachings of the present invention.
• the term "pathogen” as used herein can be natural biological agents or artificial materials. Pathogens may include, for example, but not limited to, viruses, eukaryotic microbes, bacteria, fungi, parasites and prions. In particular, pathogens can be a canine parvovirus of the parvoviridae family or a vaccinia virus of the poxviridae family.
• target material is the pathogen that is to be detected.
• target sample is a substance that is being tested to determine whether the target material is contained therein.
• target samples can be natural or man-made substances.
• the target sample may be a biologically produced product or an artificially made product.
• the target samples may be a solution, gas, or other medium.
• deposition material or "deposited material” is the material deposited on the chip for which the target material has some known affinity, such as a binding agent. The deposition material can be deposited in a deposition domain, otherwise known as an affinity domain.
• the deposition material and the target material can undergo a non-specific binding event, such as, but not limited to, non-specific electrostatic or hydrophobic interactions, or a specific molecular interaction event, such as covalent or ionic attachment.
• Such deposition materials can include, but are not limited to antibodies, proteins, peptides, nucleic acids, peptide aptamers, or nucleic acid aptamers.
• the deposited materials are antibodies to known viral pathogens.
• Antibodies are proteins that bind specifically to a target.
• the present example illustrates the detection of viruses as the target material.
• the deposition material is the corresponding antibody.
• the antibody is a naturally occurring or synthetic protein that binds specifically to the target.
• Canine parvovirus (CPV) and vaccinia virus were detected.
• CPV belongs to the Parvoviridae family of viruses and is among the smallest viruses known. Parvoviruses are among simplest eukaryotic viruses and were only discovered in the 1960's. Parvoviral particles are icosahedral, 18- 26 nm in diameter and consist of protein (50%) and DNA (50%). The virions are not enveloped and the nucleocapsid confers considerable stability to the particles.
• Infectious virions of CPV contain 60 protein subunits, predominantly VP2.
• Vaccinia virus belongs to the poxvirus family and is among the largest viruses known.
• the vaccinia virus is an analog of smallpox, a designated biowarfare material. Furthermore, the vaccinia viruses are the largest of the DNA viruses affecting humans.
• the vaccinia virus is enveloped; slightly pleomorphic; ovoid, or brick-shaped.
• the viral particles are 140-260 nm in diameter and around 220-450 nm long.
• the viral particle is composed of an external coat containing lipid and tubular or globular protein structures enclosing one or two lateral bodies and a core, which contains the genome. Nucleocapsids are brick- shaped to ovoid.
• the core is usually biconcave with two lateral bodies.
• a substrate must first be prepared. Substrates were prepared using #1 glass cover slips (Fisher Scientific) that were cut into 7 mm X-7 mm squares and cleaned thoroughly for 30 min in ethanol using an ultrasonic bath. The glass substrates can be stored in ethanol until ready for use. The glass substrates were then coated with a thin layer ( ⁇ 3 nm) of chromium at 0.1 nm/s followed by the deposition of 20 nm gold at 0.2 nm/sec using an EBC 2000 (South Bay Technologies).
• #1 glass cover slips (Fisher Scientific) that were cut into 7 mm X-7 mm squares and cleaned thoroughly for 30 min in ethanol using an ultrasonic bath. The glass substrates can be stored in ethanol until ready for use. The glass substrates were then coated with a thin layer ( ⁇ 3 nm) of chromium at 0.1 nm/s followed by the deposition of 20 nm gold at 0.2 nm/sec using an EBC 2000 (South Bay Technologies).
• the surface was patterned by placing a copper electron microscopy grid (400 mesh, hole size 100 um, bar size 15 um) (Electron Microscopy Sciences) on the glass during the coating process forming 100 um 2 gold pads on the glass surface.
• a slot grid 200 x 600 um
• a single hole grid 600 nm
• antibodies bind tenaciously to bare (clean) gold surfaces and retain some level of biological activity.
• the virus particles can also bind to gold and create a background problem.
• Protein G is utilized as a layer over the surface because protein G presents four binding sites and orients the antibodies. Protein G is a naturally occurring protein that binds tightly to the Fc region of antibodies, in particular, IgG. In addition, when an antibody is deposited on the protein G, each antibody will orient in a specific manner relative to the surface. Control of the manner in which the antibodies orient relative to the surface insures that more of the active antibody binding site is exposed and active.
• another protein can be used, for example, protein A (similar to protein G) or a hybrid protein A/G, (a recombinant mixture of protein A and protein G that combines the binding characteristics of both).
• the chip may utilize the deposited gold surface to bind the antibody to the surface in a nonspecific way.
• the gold surface can be covered with an alkanethiolate material so that the deposited antibody coupled to the surface in a very specific manner, e.g., chemically (see Example II below).
• the glass substrates with the freshly prepared gold pads are immersed in a protein G (Sigma) solution at lmg/ml in IX PBS (lOmM phosphate buffer, 137mM NaCl and 1.37mM KC1) at room temperature for 30 minutes. Protein G is passively absorbed onto the prepared gold surface forming a uniform protein surface over the gold coated glass substrates. The substrate was then removed from the protein solution, washed with filtered distilled water, blown dry with argon, and stored at 4° C until antibody deposition.
• a protein G Sigma
• Antibodies can be deposited on the surface using a microjet device similar to the inkjet used in a inkjet printer.
• the microjet apparatus and method uses an aerosol microdroplet to create domains of the antibody on the surface.
• a single microjet, with a 30 um nozzle, and a Microjet III controller (MicroFab Technologies, Inc., Texas) was used.
• the microjet was mounted on custom-built computer controlled stage with translation along the X, Y and Z axes. Deposition domains of anti-viral antibodies on the order of few tens of microns were created in the protein G surface.
• the microjet method offers the advantage of extensive field testing and previous utilization in commercial applications involving genome arrays.
• the microjet uses a piezoelectric pump for precise delivery of fluids in the nanoliter to picoliter range.
• the microjet can consistently make arrays of antibodies with spot sizes in the 30-80 um diameter range separated by 20 um. Using spot sizes of 50 um and inter spot distance of 20 um, production of a 2 X 2 array in a 120 X 120 um area can be achieved.
• the AFM scan range is approximately 120 um and therefore can interrogate all four spots in a single AFM scan field.
• the substrates were re-hydrated by placing them in a high humidity environment for 30 minutes, such an environment may be greater than 50% more preferably about 90%. Exposing the chip to high humidity and re-hydrating the chip helps the antibody to bind to the protein G surface.
• Typical viral diameters may range from about 20-200 nm. It is not crucial for every antibody to retain biological activity, therefore, because the viral particles are significantly larger than a single antibody and will cover a field of several antibodies.
• a virus with a radius of 25 nm (roughly the size of the CPV) would cover an area of about 500 nm 2 when touching a surface with sufficient molecular flexibility to permit antibodies to gain access to 25% of the viral surface.
• the antigen binding site of an antibody covers a spatial envelope of approximately 2 nm x 5 nm, or 10 nm . Therefore, if only 20% of the antibodies on the surface were correctly oriented and biologically active, the viral particle would contact about 10 potential binding sites. Based on these considerations the present embodiment uses chemisorbed antibodies for the construction of the solid state viral detection and identification assay.
• the chip is then exposed to the target sample and tested for any molecular interaction events between the deposited material and the target material.
• the present invention utilizes an atomic force microscope as the detection apparatus.
• an AFM the interactions between a sharp, micron-scale probe and a sample are monitored and regulated as the probe scans over the sample. Extremely fine control of the motion of the AFM probe is achieved using piezoelectric crystals.
• the AFM is capable of ⁇ 2 nm lateral resolution and ⁇ 1 nm vertical resolution. This level of resolution gives the AFM the ability to detect changes in topography in the Angstrom range.
• the ability of AFM to detect height changes on the order of lnm has been utilized for the detection of antibody-antigen interaction; AFM has also been used to image nucleic acids, proteins, viruses, bacteria, live cells and other biological materials.
• the AFM can be operated in solution and is capable of identifying molecular binding events in near-real time.
• the change in height is on the order of 1-3 nanometers (nm), providing a change in signal of 100%) (from 3 to 6 nanometers, for example).
• this change is much greater, on the order of 30 to 300 nm, providing a signal to noise ratio of 10 to 100 fold.
• the present embodiment utilizes the AFM as a label-free detection device
• alternative methods including, but not limited to, surface plasmon resonance, mass spectrometry, electronic signature, optical methods, or other techniques, can be incorporated into the present invention without changing the nature and scope thereof.
• CPN is detected by constructing a chip with anti-canine parvovirus monoclonal antibody deposited thereon, exposing the chip to a target sample, and then reading the chip using the AFM to determine whether CPV is bound to the chip surface.
• the viral particles were prepared at a stock concentration of 0.3 mg/ml. Purified monoclonal antibody which recognizes the CPV capsid, A3B10 (0.9mg/ml) was utilized. In another test run, purified anti-canine parvovirus monoclonal antibody (2mg/ml) was obtained from a separate source (Custom Monoclonal International, California) with no observable change in results.
• a chip with a protein G coated surface was used for the deposition of antibodies against CPV at specific regions.
• the domains were formed using the above described microjet method.
• the antibodies of the present embodiment were diluted to O.lmg/ml in 1 X PBS before being deposited onto the surface using the microjet.
• the microjet was back- loaded with a syringe, and the antiviral antibodies were deposited on the surface with spot sizes in the range of 40 to 80 um. After all the antibodies spots were deposited, the chips were incubated in a humid environment for 30 minutes at room temperature to allow the antibodies to bind to ' the protein G surface. The chips were then washed with distilled water, blown dry with Argon and stored at 4° C until used.
• the chip was washed with distilled water and imaged to insure the surface was clean and smooth with no particulate matter thereon. Such an image is seen in FIG. 7a and 6a.
• the present embodiment utilized incubation of the antibody with the chip to expose the deposition material to the target material.
• the chips were incubated with the target sample, in this case 200 ⁇ l of virus detection buffer (PBS containing 0.25 mM NaCl, and 0.2% tween-80) on a rocker platform at room temperature for 15 min.
• virus detection buffer PBS containing 0.25 mM NaCl, and 0.2% tween-80
• each chip was imaged and a particle count analysis was performed.
• Five sets of data were collected and plotted on a graph with the time on the X-axis and number of virus particles bound on the Y-axis. As seen in FIG. 8, as the concentration decreases the number of virus particles bound at any given time also decreases. Also, at any concentration the binding profile seems to follow a standard asymptotic curve as would be seen for a single step binding profile.
• the bindings where no CPV antibody was deposited can be attributed to nonspecific interactions between the virus with the protein G surface. See FIGS. 7a- c. [056] By performing a dilution series experiment with CPV, it was determined that virus particles can be detected at a concentration of 300 pg/ml.
• the CPN genome is about 5 kilobases of single stranded D ⁇ A. Assuming the molecular weight of the total D ⁇ A is equal to that of the proteins, the molecular weight of the empty capsids would be about 2000 kDa., then 1 ⁇ g of the empty capsids would have about 3 X 10 u particles (stock concentration of 10 14 particles/ml). These numbers indicate that viruses at a titer of 10 7 particles/ml will provide a signal that is sufficient to report the presence of a particular virus. [057] More quantitative data analysis can be performed to relate the degree of observed binding to the sample concentration.
• the number of particles observed is a function of time, which is derivative of the sample concentration, it is possible to carry out a time course and determine an absolute sample concentration.
• the number of viruses bound at several time points for example, 1, 5, 20 and 60 minutes, is measured. This can be compared to a standard curve for virus at known concentrations. Since the binding is driven by diffusion and therefore the number of binding events per unit time is a function of concentration, one can calculate the concentration of the unknown virus by fitting the binding vs. time curve to the standard curve obtained using the known concentrations of virus.
• FIGS. 7a-c represent AFM scans of a chip surface.
• the upper image shows a two dimensional rendering in which scale indicates topographical features. Lighter intensity features are taller than darker features (total Z range
• FIG. 7b shows the surface after reaction with CPV.
• the lighter features correspond to the presence of bound CPV particles.
• each antibody specific for a unique virus can be spotted on a distinct domain.
• viral particles will bind strongly to the domain with its specific antibodies but will also non-specifically bind weakly to other domains. See FIG. 6b.
• most of the weak, non-specific binding of the antigen is removed and remaining surface binding of the antigen is specific to the domain with its antibody. See FIG. 6c.
• the results of binding can be checked by utilizing a control. A control is effectuated by exposing the virus to a chip, which does not have a binding affinity to the target material.
• FIG. 7a shows the chip surface as detected by AFM with no analyte added (control).
• FIG. 7c shows a chip against Transmissible Gastroenteritis Virus (TGEV), reacted with CPV, which should not bind to the anti-TGEV antibody on the chip (non-specific binding). In this case, very little non-specific binding occurs, as reflected by the absence of raised features (viral particles).
• TGEV Transmissible Gastroenteritis Virus
• Such a rendering was also performed with antibodies against CDV (Canine Distemper Virus) with similar results.
• CDV Canine Distemper Virus
• Anti-vaccinia and anti-adenovirus (control) antibodies were obtained from Biodesign.
• Vaccinia virus strain WR American Type Culture
• HeLa S3 ATCC CCL-2.2 cells maintained on RPMI 1640 supplemented with 7% v/v fetal bovine serum and penicillin, streptomycin and fungizone. Near confluent S3 cells in Blake bottles were infected at a multiplicity of infection (MOI) of 0.2. Cells were collected when detachment became apparent in about 3 days.
• Virus was purified from frozen and thawed cells by successive cycles of sedimentation velocity and equilibrium density centrifugation. Stocks of purified virus were titered by end- point dilution assays and stored at -80C. The virus had a stock concentration of 10 7 pfu/ml.
• the purified rabbit anti-vaccinia B65101R lot 8304600
• goat anti adenovirus hexon B65101G, lot 4A01901
• the process of active immobilization to adhere anti-vaccinia antibodies to the chip surface was utilized instead of the passive adso ⁇ tion to a protein layer as described in Example I above.
• few adenovirus particles bind to the vaccinia chip demonstrating the specificity of vaccinia chip.
• Further characterization of the vaccinia chip showed that the binding of vaccinia to the chip was linear with time for the first 12 hours with a maximum of 200 particles attached in a 900 ⁇ area viewed by AFM.
• the anti-vaccinia binding agent can be tethered to the surface by first placing an alkanethiolate monolayer over the gold. The anti-vaccinia virus would then be reacted with a -COOH group on the exposed portion of the alkanethiolate.
• the binding agent can be tethered with a succinimide group or a NH 2 group.
• the virus retains its typical brick-like mo ⁇ hology.
• the virus may retain some or all of its infectivity as the placement of the washed and dried chip onto a HeLa S3 monolayer resulted in infection from which infectious vaccinia virus was obtained.
• the anti-adenovirus antibody in the heterologous experiment did exhibit a few bound virions.
• the ratio of homologous to heterologous signal in several experiments using these antibodies is about one log.
• 3-8 vaccinia particles were detected in a 900 ⁇ field using anti-adenovirus.
• EDC Dimethylaminopropyl)carbodiimide
• MES (2-(N- Mo ⁇ holino)ethanesulfonic acid) buffer pH 4.8
• Each chip was rinsed in PBS and blown dry in a stream of dry argon.
• the central gold pattern formed by the slot grid) were covered with 1 ⁇ l of the antibodies (0.1 mg/ml in PBS) and incubated at room temperature for 2 hours.
• the chips were then rinsed in PBS and the un-reacted chip surface was blocked by incubating in 10 mM methylamine in PBS for 30 minutes.
• the chips were washed with water, blown dry and stored at 4 C.
• larger spots can be used in conjunction with a mechanism for rapid translation of the sample under the scanning probe.
• spot sizes of 60-100 ⁇ diameter can be positioned a few tens of microns apart in the array.
• the AFM would then scan the spots in a known order, relying on accurate translation of the spots to the interrogation field. This operation may be readily accomplished using a conventional high resolution translation stage. Throughput would not be compromised because faster scan rates (e.g., 3 Hz vs. 1 Hz) and lower resolution (e.g. 256 vs. 512 lines per scan) data could be employed to offset the additional time required to physically translate the stage without introducing intolerable degradation of data.
• faster scan rates e.g., 3 Hz vs. 1 Hz
• lower resolution e.g. 256 vs. 512 lines per scan
• the invention can be applied to detection and characterization of a broad range of biological materials, such as, but not limited to, other viruses, bacteria, bacterial spores, prions, pathogenic microbes such as fungus, parasites, mold, and pollen spores.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Immunology (AREA)
• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Molecular Biology (AREA)
• Hematology (AREA)
• Biomedical Technology (AREA)
• Urology & Nephrology (AREA)
• Biotechnology (AREA)
• Physics & Mathematics (AREA)
• Microbiology (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• Analytical Chemistry (AREA)
• Cell Biology (AREA)
• Medicinal Chemistry (AREA)
• Food Science & Technology (AREA)
• Virology (AREA)
• General Physics & Mathematics (AREA)
• Pathology (AREA)
• Organic Chemistry (AREA)
• Proteomics, Peptides & Aminoacids (AREA)
• Inorganic Chemistry (AREA)
• Tropical Medicine & Parasitology (AREA)
• Wood Science & Technology (AREA)
• Zoology (AREA)
• Biophysics (AREA)
• Bioinformatics & Cheminformatics (AREA)
• General Engineering & Computer Science (AREA)
• Genetics & Genomics (AREA)
• Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)
• Apparatus Associated With Microorganisms And Enzymes (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (2)

Family

ID=29709705

Family Applications (1)

Country Status (8)

Cited By (2)

Families Citing this family (36)

Family Cites Families (113)

• 2002
  • 2002-05-30 US US10/160,372 patent/US6897015B2/en not_active Expired - Lifetime
• 2003
  • 2003-05-29 CN CNA038118688A patent/CN1656236A/zh active Pending
  • 2003-05-29 JP JP2004508645A patent/JP2005527830A/ja active Pending
  • 2003-05-29 EP EP03734244A patent/EP1513954A4/en not_active Ceased
  • 2003-05-29 KR KR1020047019317A patent/KR20050026395A/ko not_active Withdrawn
  • 2003-05-29 WO PCT/US2003/016860 patent/WO2003101278A2/en not_active Ceased
  • 2003-05-29 AU AU2003238783A patent/AU2003238783A1/en not_active Abandoned
  • 2003-05-29 CA CA002487792A patent/CA2487792A1/en not_active Abandoned

Also Published As

Similar Documents

Legal Events