Publications by authors named "Hiromi Brown"

Forensic casework samples often include human hairs, teeth, and bones. Hairs with roots are routinely processed for DNA analysis, while rootless hairs are either not tested or processed using mitochondrial DNA. Bones and teeth are submitted for human remains identifications for missing persons and mass disaster cases.

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The Sperm X method uses a nanotechnology derived polymer membrane that functions as a separation medium to effectively trap sperm cells while enabling efficient flow through of the digested epithelial cell DNA. This specialized membrane enabled development of a method that could significantly increase a forensic laboratory's ability to obtain male sperm fraction DNA profiles. The SpermX device provides a rapid, reproducible procedure that is easy to implement in a single-tube format as well as high-throughput truly automated hands-free workflows.

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Background: Liquid biopsy is a new area in cancer diagnostics that measures cell-free DNA in plasma from tumor that may serve as a monitoring tool in colorectal cancer patients.

Methods: Multiplexed real-time polymerase chain reaction based on multicopy retro-transposable elements (targeting 80 base pair and 265 base pair sequences and an internal-positive-control) was used to evaluate the ability of cell-free DNA concentration and DNA Integrity Index to discriminate cancer from healthy patients. A cohort of 40 healthy controls and 39 stage IV colorectal patient's plasma were interrogated.

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Historically, rootless hair shaft samples submitted to a forensic laboratory for DNA analysis are reserved for mitochondrial DNA (mtDNA) analysis due to the presence of highly degraded as well as insufficient amounts of nuclear DNA. Although mtDNA has been very successful in obtaining results from rootless hair, this system has its limitations, namely, it is a lineage marker that cannot differentiate between maternally related genotypes. Given the high incidence of hairs as forensic evidence, there is a need for the use of a nuclear DNA test system capable of producing reliable results for hair shaft forensic evidence.

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We report the findings of the evaluation of the InnoTyper 21 genotyping kit for the use of human identification (HID) and paternity testing in South Africa. This novel forensic kit evaluates 20 retrotransposable elements (AC4027, MLS26, ALU79712, NBC216, NBC106, RG148, NBC13, AC2265, MLS09, AC1141, TARBP, AC2305, HS4.69, NBC51, ACA1766, NBC120, NBC10, NBC102, SB19.

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The development and validation of InnoQuant HY, a real-time PCR system containing four DNA targets-two RE autosomal targets of different sizes, male specific targets, and an internal positive control target-are described herein. The ratio of the two autosomal targets provides a Degradation Index, or a quantitative value of a sample's degradation state. The male specific targets are multi-copy targets located on the Y chromosome, which provides information about a sample's male DNA composition.

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We report here a novel multiplexed DNA analysis system consisting of 20 Alu markers and Amelogenin for analysis of highly degraded forensic biological samples. The key to the success of the system in obtaining results from degraded samples is the primer design yielding small amplicon size (60-125bp) for all 20 markers. The markers included in the InnoTyper 21 system are bi-allelic, having two possible allelic states (insertion or null) and thus termed INNULs.

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This study examines the relationship between the DNA binding thermodynamics and the enzymatic activity of the Klenow and Klentaq Pol I DNA polymerases from Escherichia coli and Thermus aquaticus. Both polymerases bind DNA with nanomolar affinity at temperatures down to at least 5°C, but have lower than 1% enzymatic activity at these lower temperatures. For both polymerases it is found that the temperature of onset of significant enzymatic activity corresponds with the temperature where the enthalpy of binding (ΔHbinding) crosses zero (TH) and becomes favorable (negative).

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Understanding the thermodynamics of substrate selection by DNA polymerase I is important for characterizing the balance between replication and repair for this enzyme in vivo. Due to their sequence and structural similarities, Klenow and Klentaq, the large fragments of the Pol I DNA polymerases from Escherichia coli and Thermus aquaticus, are considered functional homologs. Klentaq, however, does not have a functional proofreading site.

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