Category Archives: Biomedical Research Tools

Animal models, antibodies, cell lines, reagents, vectors, etc.

Simple, cost-effective, flexible system for micro/nano particle manipulation

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Summary:

The availability of mobile magnetic traps offers new control needed for rapid progress at the frontiers of several branches of science and engineering. Ohio State researchers have discovered a way to create tunable mobile traps along a nanowire, which allows the manipulation and movement of nanoparticles along the wire. The femto- to pico-Newton scale forces possible with this method, which are delivered using electric currents, are ideally suited for probing single microparticles and biomolecules in the 10 nanometer to 100 micrometer length scales. Additionally, the nanoparticle(s) can be tethered to larger molecules, allowing manipulation of the larger molecules. As an example, a DNA strand could have each end attached to separate nanoparticles and then stretched as the nanoparticles are moved away from each other.

Potential Applications:

  • Clinical diagnosis
  • Biomolecule analysis
  • Forensics
  • Enviromental analysis
  • Nanofluidics

Advantages:

  • Easy to engineer magnetic domain
  • Simple and accurate manipulation of nanoparticles
  • Real-time observation of single or multiple objects trapped along the nanowire
  • Uses electric currents to transport along predetermined pathways
  • Two or more functionalized particles at the mobile traps can be linked to create a planar magnetic tweezer stage

Non-blinking, Color-changing Quantum Dot Composite Nanoparticles

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Summary:

Quantum dots are fluorescent nanoparticles (<50 nm) with known applications including single molecule tracking, cell tracking, flow cytometry, and in vivo imaging.  A major challenge with the use of quantum dots in settings where a single quantum dot is conjugated to a single target for tracking purposes is blinking of the quantum dot.  Blinking is the result of the random switching of the fluorescence of the quantum dot from the on-state to the off-state.  This phenomenon is particularly problematic in tracking applications because the trajectories of the targets being tracked are broken.  In the past few years several designs of "non-blinking quantum dots" have been reported.  Blinking, however, is the best (and often the only feasible) in situ indicator of particle aggregation status in tracking studies.  The ability to make sure individual (or small aggregates of) molecules/particles rather than large aggregates are being tracked is crucial in tracking studies. 

Researchers at OSU have solved these two seemingly irreconcilable problems simultaneously by developing quantum dot composite nanoparticles with two key features: blinking-reduction and color-changing, the latter of which permits easy aggregation status evaluation in situ.  The strategy of producing quantum dots of multiple colors into a nanocontainer (micelle).  Because blinking dynamics of different quantum dots are out of phase, OSU’s composite nanoparticles emit uninterrupted color-changing fluorescence, with color-changing serving as the aggregation-status indicator. 

Continuous color-changing fluorescences of the Quantum Dot Composite Nanoparticles can provide scientists both the ability of imaging single (or small aggregates of) targets for long-term studies and the confidence of knowing that they are indeed imaging single (or small aggregates of) targets in tracking studies of biological processes.  Additional features of these novel fluorescent nanoparticles developed at OSU include ease of synthesis and bioconjugation, small size, high tolerance to biological environments, and ability to distinguish particle moving out-of-focus from blinking, which is another longstanding problem in quantum dot-based tracking.

Publications
Ruan, G. & Winter, J.O. Alternating-color quantum dot nanocomposites for particle tracking. Nano Letters (published on web Feb 15 2011).

Ruan, G. & Winter, J.O. Multi-color Nanoparticles for Single Particle Tracking.  American Institute of Chemical Engineers Annual Meeting, Salt Lake City 2010. 

Differentially Expressed in Squamous Cell Carcinoma Gene 1

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Summary:

Researchers at The Ohio State University have provided a novel method for diagnosing and treating squamous cell carcinoma and prostate cancer. This invention is based upon the detection of a specific gene (serine protease gene) encoding a human protein called Differentially Expressed in Squamous Cell Carcinoma Gene-1 or “DESC1″. The invention also provides for DESC1 vectors, host cells, antibodies directed to DESC1 polypeptides, hybridization probes, and primers useful in the method of detecting DESC1 mRNA.

Squamous cell carcinoma is the second most common form of skin cancer. This condition is typically diagnosed by visual examination of the morphological characteristics (shape, form, arrangement, etc.) of tissue samples by a cytologist or pathologist. The potential for human error inherent in these methods has thus made it desirable to develop more reliable and efficient techniques. Investigation into the underlying genetics of the disease has led to the identification of several genes of interest. The DESC1 gene, for instance, is expressed in significant levels in epithelial tissues of the head, neck, oral mucosa, tonsils, prostate, testes, and skin in healthy individuals. However, the gene is repressed in squamous cell carcinoma of the head, neck, prostate, and testes, as compared to normal tissue specimens. It has also been determined that DESC1 is not expressed in colon carcinoma, lung carcinoma, melanoma, or HeLa cells. This gene may prove a useful marker for the detection and treatment of squamous cell carcinoma and other skin cancers.

Potential Applications:

  • Diagnosing squamous cell carcinoma, prostate cancer, and other epithelial cancers in a tissue sample.
  • Therapeutic gene to treat squamous cell carcinoma, prostate cancer, and other epithelial cancers.

Advantages:

  • Differential expression of DESC1 permits a novel and improved method for diagnosing squamous cell and prostate carcinoma without the need for visual examination.
  • Expression of DESC1 can be determined using conventional procedures.
  • Down regulation of DESC1 during the progression of squamous cell carcinoma may provide a basis for therapeutic targets.

IgE antibody regulation

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Summary:

Researchers at The Ohio State University have identified a unique signaling pathway that is activated under physiological conditions and by selective drugs to regulate the level of IgE antibody produced by B cells. The pathway regulates IgE without affecting IgG antibody production, thereby allowing for creation of new allergic asthma therapies that do not depress the overall activity of the immune system. The development of these therapies may reduce patient dependency on current allergic asthma therapies and could decrease a patient’s risk of asthma-related death. The discovery of the pathway may provide therapeutic targets for reducing allergic asthma symptoms during periods of stress. The pathway may help patients avoid the time-dependent decreases in efficacy that characterize asthma drugs currently on the market.

Potential Applications:

  • Pharmaceutical market
    • Allergic asthma therapies
    • Allergy therapies
    • Eosinophilic esophagitis therapies
    • Therapies to treat parasitic infections
  • Scientific research
    • Specific phosphatase inhibitors

Advantages:

  • Novel pathway targeted by ß2-adrenergic receptor
  • Pathway specific to regulation of IgE
  • Independent of baseline IgE production

Yeast Artificial Chromosomes (YAC) Containing Entire Transcript Unit of Human AFGF

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Summary:

cDNA and sequence, newt FGFR2 cDNA and sequence, newt FGFR3 cDNA and sequence, newt KGFR cDNA and sequence, and CHO-KL cell line (KPTr2-2) expressing newt KGFR. Mutant cell lines (Tr31-5-1 and Tr33-1-2) that become non-responsive to aFGF stimulation are used to differentiate biological activities among different forms of aFGF and other FGF proteins. These novel sequences and cell lines substantially enhance the availability of newt acidic fibroblast growth factor and are useful for producing compositions for promoting growth and/or wound healing.

Potential Applications:

Treatment of acute nonlymphocytic leukemia (ANLL) or myelodysplastic syndrome (MDS)

Advantages:

  • Possible cloning of tumor suppression gene
  • Promote growth and/or wound healing

Multi-Degree-of-Freedom Nano-Probes: Design, Actuation, and Measurement

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Summary:

In applications such as scanning probe microscopy (e.g. AFM), nano-metrology, and micro/nano manipulation, traditional nano-probes are limited in that their tips have a fixed orientation. As a result, they are useful primarily for near-planar samples. Complex geometrical features or features with large changes in topography can either not be imaged at all or are imaged at greatly reduced lateral resolution with increased artifacts. Researchers at the Ohio State University have developed a novel multi-axis nano-probe that enables high-resolution imaging of 3-D surfaces on arbitrarily complex geometric features and nano-manipulation of 3-D samples. For these applications, the probe enables fast and precise co-located control of tip orientation by several tens of degrees and multi-axis control of probe-sample interaction forces. Together, they allow for controlled 3-D manipulation of soft, sensitive specimens and imaging samples with complex geometry (like re-entrant features and steep side-walls).

Potential Applications:

  • AFM equipment manufacturers
  • Nanometrology instrument manufacturers
  • Nanomanipulation system manufacturers
  • NEMS/MEMS manufacturers

Advantages:

  • Enables control of probe-orientation along two independent axes by several tens of degrees while retaining the probe-stiffness along the Z-axis
  • Compact, high-bandwidth, high-gain actuation for fast, large-angle tip-positioning
  • Enables the measurement of tip orientation angles that are possibly over a hundred times larger than the measurement range of the optical detectors used in scanning probe microscopy while retaining the high resolution of the detectors
  • Enables multi-axis co-located control of probe-sample interaction forces
  • Enables real-time tracking of surface orientation by the probe-tip during 3-D imaging of sample surfaces

Modified Serial Analysis of Ribosomal Sequence Tags (mSARST)

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Summary:

Knowledge of bacterial diversity is a critical step in understanding and manipulating microbial communities and processes, ranging from environmental bioremediation to improving human health. Researchers at The Ohio State University have significantly improved a novel method for rapidly and comprehensively analyzing bacterial diversity. Serial Ribosomal Sequence Tags (SARST) is a newly described method of examining microbial diversity, and we have developed a modified version of SARST (mSARST) that greatly improves the efficacy of the approach. Both methods use a series of enzymatic reactions to produce concatemers of ribosomal sequence tags that can be cloned sequenced, but mSARST can be readily adapted to a kit-based format and offers up to a 20-fold increase in throughput over traditional clone libraries. To our knowledge, mSARST is also the only cloning technology available to provide both qualitative and quantitative information about the structure of microbial communities, in a high throughput format.

Potential Applications:

  • Characterization of any type of microbial community irrespective of the level of complexity.
  • Comprehensive studies of human gastrointestinal microbiology in support of the prediction and diagnosis of illness and disease.
  • Comprehensive analysis and monitoring of the temporal or spatial changes in microbial diversity in complex natural and managed microbial communities, for quality control and quality assurance purposes.
  • Fundamental studies of microbial ecology.

Advantages:

  • Provides more detailed, rapid and cost effective analysis of bacterial diversity and community structure than previously possible.
  • Offers up to 20-fold increase in throughput over traditional clone libraries.
  • Bias and chimera formation associated with PCR-based analysis is minimized.
  • RSTs can be used to design microarrays for further analysis.
  • Procedure can be packaged into a commercial reagent kit.

Plasma microRNA profile to detect ovarian cancer

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Summary:

MicroRNAs (miRNA) were discovered that can serve as biomarkers or treatment targets for ovarian cancer. A method was developed to isolate RNA from serum samples and perform a real-time PCR-based microarray for miRNAs using a small sample of serum RNA. RNA was isolated from the serum of patients with ovarian cancer. MicroRNAs (miRNA) were amplified by real-time PCR-based microarray and analyzed. Five miRNAs were overexpressed and three miRNAs were under-expressed in the serum of ovarian cancer patients compared to normal controls. Some of the overexpressed miRNAs are known oncogenes that have therapeutic and biomarker potential.

Potential Applications:

  • Early serum biomarkers for the detection of ovarian cancer (especially for patients with normal CA-125) or risk of ovarian cancer
  • Method for analysis of miRNAs in the serum
  • MicroRNA targets for treatment of ovarian cancer by regulating protein expression by modulating miRNAs

Advantages:

  • RNA extraction from small patient serum samples (250 uL)
  • Novel real-time PCR microarray approach (containing 365 miRNA targets) for identification of microRNAs in RNA samples
  • Microarray platform permits screening of large numbers of miRNAs with small samples of serum RNA (400 ng)
  • Unique profile of microRNAs for the early diagnosis of ovarian cancer was discovered
  • Serum microRNAs were identified that can serve as normalizers

Methods for Identifying Nucleic Acid Mutations using Mismatch Modification

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Summary:

Researchers at The Ohio State University have developed a method for the rapid and efficient identification of genetic alterations within large fragments of DNA (>3.2 Kb). Genetic alterations form the basis of many cancers and all inherited diseases. In cancer, there is growing evidence that identification of genetic mutations in the early stages of disease could lead to early interventional treatments that have a greater potential to reduce the morbidity and mortality caused by end-stage disease. This method describes a novel procedure to detect mutated DNA using chemical modifications that carry an easily detectable, antigenic marker. These components can be packaged into a molecular diagnosis kit resulting in rapid, efficient and sensitive detection of genetic mutations. Mutations can then be analyzed to determine the degree to which they are disease-related as well as providing a basic research tool for genetic studies. There is a clear need for the development of rapid, reliable, and sensitive methods for detecting point mutations in nucleic acids. It is anticipated that this technology will provide significant improvements to the interdisciplinary fields of mutation detection and genetic screening.

Potential Applications:

  • Early detection and diagnosis of genetically linked diseases.
  • Provides a basic research tool for the study of genetic mutations.

Advantages:

  • It’s non-radioactive, utilizes no harsh or dangerous chemicals, is conducted within a single tube, is extremely rapid, screens tremendously large fragments of DNA and can easily be adapted to automated formats.
  • This method allows for mutations to be identified and segregated from the overwhelming amounts of normal DNA.

Bioluminescent Variants of Tomato Canker Bacteria (Clavibacter michiganensis subspecies michiganensis)

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Summary:

Tomato Canker is a bacterial disease caused by Clavibacter michiganensis subspecies michiganensis (Cmm). Currently there are no resistant strains of tomatoes for this important bacterial disease. OSU scientists have developed a bioluminescent strain of Cmm, which will be useful to identify and isolate strains of Cmm that have reduced virulence for tomato plants. Bioluminescence is a very rapid and sensitive technique for identification of live bacterial numbers in plants since the bacteria emit light that can be imaged with a real-time imaging system. Bioluminescence is due to expression of the Lux operon of genes in recombinant bacteria. If the Lux genes are inserted into a bacterial virulence gene, then that bacterial strain would have reduced virulence and growth in tomato plants. The virulence gene can be readily identified and cloned from the bioluminescent bacteria. In addition, bioluminescent strains of Cmm can be used to rapidly screen antibiotics and bactericides that have efficacy to kill these bacteria.

Potential Applications:

  • Development of Tomato plant varieties resistant to Canker.
  • Development of recombinant genes or biological controls for Tomato Canker.
  • Development of synthetic products for control of Tomato Canker bacteria.

Advantages:

  • Bioluminescent Tomato Canker bacteria (Cmm) allow rapid screening of variants that differ in virulence and growth in tomato plants.
  • Reduced virulence strains of Tomato Canker bacteria (Cmm) can be isolated.
  • Virulence genes of Tomato Canker bacteria can be identified.
  • Antibiotics and bactericides can be screened for their ability to kill Tomato Canker bacteria.