University of California

Los Alamos National Security, LLC

Peter C Stark

Cheryl R Kuske

John M Dunbar

Michael D Ward

Luis Humberto Garcia-Rubio

José A Olivares

Eduardo Zurek

Jeffrey V Wheat

Gustavo Roybal

Karen K Hill

Jos&eacute; A Olivares

Kenneth I Mullen

There is provided a method and device for remote sampling, preparation and optical interrogation of a sample using light scattering and light absorption methods. The portable device is a filtration-based device that removes interfering background particle material from the sample matrix by segregating or filtering the chosen analyte from the sample solution or matrix while allowing the interfering background particles to be pumped out of the device. The segregated analyte is then suspended in a diluent for analysis. The device is capable of calculating an initial concentration of the analyte, as well as diluting the analyte such that reliable optical measurements can be made. Suitable analytes include cells, microorganisms, bioparticles, pathogens and diseases. Sample matrixes include biological fluids such as blood and urine, as well as environmental samples including waste water.

Portable sample preparation and analysis system for micron and sub-micron particle characterization using light scattering and absorption spectroscopy

An electrophoretic device separates and detects particles such as DNA fragments, proteins, and the like. The device has a capillary which is coated with a coating with a low refractive index such as Teflon&#xae; AF. A sample of particles is fluorescently labeled and injected into the capillary. The capillary is filled with an electrolyte buffer solution. An electrical field is applied across the capillary causing the particles to migrate from a first end of the capillary to a second end of the capillary. A detector light beam is then scanned along the length of the capillary to detect the location of the separated particles. The device is amenable to a high throughput system by providing additional capillaries. The device can also be used to determine the actual size of the particles and for DNA sequencing.

Particle sizer and DNA sequencer

An automatic sample collection system for use with an electrophoretic slab gel system is presented. The collection system can be used with a slab gel have one or more lanes. A detector is used to detect particle bands on the slab gel within a detection zone. Such detectors may use a laser to excite fluorescently labeled particles. The fluorescent light emitted from the excited particles is transmitted to low-level light detection electronics. Upon the detection of a particle of interest within the detection zone, a syringe pump is activated, sending a stream of buffer solution across the lane of the slab gel. The buffer solution collects the sample of interest and carries it through a collection port into a sample collection vial.

Sample collection system for gel electrophoresis

A method for quantitating dsDNA in an aqueous sample solution containing an unknown amount of dsDNA. A first aqueous test solution containing a known amount of a fluorescent dye-dsDNA complex and at least one fluorescence-attenutating contaminant is prepared. The fluorescence intensity of the test solution is measured. The first test solution is diluted by a known amount to provide a second test solution having a known concentration of dsDNA. The fluorescence intensity of the second test solution is measured. Additional diluted test solutions are similarly prepared until a sufficiently dilute test solution having a known amount of dsDNA is prepared that has a fluorescence intensity that is not attenuated upon further dilution. The value of the maximum absorbance of this solution between 200-900 nanometers (nm), referred to herein as the threshold absorbance, is measured. A sample solution having an unknown amount of dsDNA and an absorbance identical to that of the sufficiently dilute test solution at the same chosen wavelength is prepared. Dye is then added to the sample solution to form the fluorescent dye-dsDNA-complex, after which the fluorescence intensity of the sample solution is measured and the quantity of dsDNA in the sample solution is determined. Once the threshold absorbance of a sample solution obtained from a particular environment has been determined, any similarly prepared sample solution taken from a similar environment and having the same value for the threshold absorbance can be quantified for dsDNA by adding a large excess of dye to the sample solution and measuring its fluorescence intensity.

Method of quantitating dsDNA

Growing community of inventors

Los Alamos, NM, United States of America

Peter C Stark