Thomas M. Yoshida

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An efficient and reliable double-stranded DNA (dsDNA) staining protocol for DNA fragment sizing by flow cytometry is presented. The protocol employs 0.8 microM of PicoGreen to label a wide range of DNA concentrations (0.5 ng/mL to 10,000 ng/mL) without regard to the solution dye/bp ratios and without initial quantification of the DNA analyte concentration.(More)
AIM We will validate sample collection methods for recovery of microbial evidence in the event of accidental or intentional release of biological agents into the environment. METHODS AND RESULTS We evaluated the sample recovery efficiencies of two collection methods - swabs and wipes - for both nonvirulent and virulent strains of Bacillus anthracis and(More)
A microscope-based system is described for directly measuring protein rotational motion in viscous environments such as cell membranes by polarized fluorescence depletion (PFD). Proteins labeled with fluorophores having a high quantum yield for triplet formation, such as eosin isothiocyanate (EITC), are examined anaerobically in a fluorescence microscope.(More)
A pulsed-field gel electrophoresis (PFGE) method was developed for discriminating Bacillus anthracis from B. cereus and B. thuringiensis. A worldwide collection of 25 B. anthracis isolates showed high-profile homology, and these isolates were unambiguously distinguished from B. cereus and B. thuringiensis isolates by cluster analysis of the whole-genome(More)
The sizing of restriction fragments is the chief analytical technique utilized in the production of DNA fingerprints. Few techniques have been able to compete with pulsed-field gel electrophoresis (PFGE), which is capable of discriminating among bacteria at species and strain levels by resolving restriction fragments. However, an ultrasensitive flow(More)
Rapid binding kinetics of SYTOX Orange stain with double-stranded DNA (dsDNA) was revealed on the DNA fragment sizing flow cytometer. We demonstrated for the first time that the dye molecules could be adsorbed onto the capillary surface and native DNA fragments can be dynamically stained while passing through the capillary. High-quality burst size(More)
We describe the application of Extreme Value Statistics to the analysis of discrete species that possess distinguishable properties (fluorescence wavelength, fluorescence intensity, light scattering, etc.) as they cross a well-defined observation/probe region. Time-gated selection and extreme value data analysis result in increased resolution in analytical(More)
Accurate measurement of single DNA fragments by DNA fragment sizing flow cytometry (FSFC) depends upon precise, stoichiometric DNA staining by the intercalating dye molecules. In this study, we determined the binding characteristics of a commercially available 532 nm wavelength-excitable dye and used this information to develop a universal DNA staining(More)
BACKGROUND The measurement of physical properties from single molecules has been demonstrated. However, the majority of single-molecule studies report values based on relatively large data sets (e.g., N > 50). While there are studies that report physical quantities based on small sample sets, there has not been a detailed statistical analysis relating(More)
Functional and structural changes accompany the differentiation of granulosa cells during follicular development. We used flow cytometry and fluorescent dyes to characterize two organelles important to the steroidogenic process. Mitochondria, which contain the rate-limiting enzyme responsible for cholesterol conversion to pregnenolone, and lipid droplets,(More)