Abstract: Disclosed herein are method of detecting the presence of living cells in a sample by detecting the death of those cells. Because cell death can occur more rapidly than cell growth, which is often the parameter used to detect living cells, detection by death can reduce the time to detect certain organisms. Further, the present methods can distinguish between the presence of dead cells which may leave traces of, for example, detectable genetic material, and living cells that are of concern in situations such as diagnosing an infection.

Abstract: An improved system and method is provided for detecting viable bacteria in a suspension sample. A sample of a suspension in which bacterial presence is suspected is collected from a source and a portion of the sample transferred to a microfluidic unit. A series of analysis signals at different frequencies are applied to the sample portion. An impedance is measured via a signal analyzer for the sample portion for each of the analysis signals to define an impedance data set. An initial bulk capacitance value is determined for a model circuit based on the impedance dataset. After a predetermined time period, a new bulk capacitance value is determined for another portion of the sample. The difference between the new bulk capacitance and the initial bulk capacitance value is compared to a threshold value to determine if viable bacterial is present in the sample.

Abstract: An improved system and method is provided for detecting viable bacteria in a suspension sample. A sample of a suspension in which bacterial presence is suspected is collected from a source and a portion of the sample transferred to a microfluidic unit. A series of analysis signals at different frequencies are applied to the sample portion. An impedance is measured via a signal analyzer for the sample portion for each of the analysis signals to define an impedance data set. An initial bulk capacitance value is determined for a model circuit based on the impedance dataset. After a predetermined time period, a new bulk capacitance value is determined for on another portion of the sample. The difference between the new bulk capacitance and the initial bulk capacitance value is compared to a threshold value to determine if viable bacterial is present in the sample.

Abstract: A multiple flow system and method for detecting substances in a fluid is provided. More specifically, a first fluid tube containing a first fluid and a second fluid tube containing a second fluid are coupled to a common fluid tube via a connector, such that alternating discrete compartments of the first fluid and the second fluid flow through the common fluid tube. The first and second fluids are immiscible. A substance detector, having a flow chamber with an internal wall, is coupled to the common fluid tube. The alternating discrete compartments of the first and second fluids flow through the flow chamber and are analyzed by the substance detector.

Abstract: An improved system and method is provided for detecting viable bacteria in a suspension sample. A sample of a suspension in which bacterial presence is suspected is collected from a source and a portion of the sample transferred to a microfluidic unit. A series of analysis signals at different frequencies are applied to the sample portion. An impedance is measured via a signal analyzer for the sample portion for each of the analysis signals to define an impedance data set. An initial bulk capacitance value is determined for a model circuit based on the impedance dataset. After a predetermined time period, a new bulk capacitance value is determined for on another portion of the sample. The difference between the new bulk capacitance and the initial bulk capacitance value is compared to a threshold value to determine if viable bacterial is present in the sample.

Abstract: An improved system and method is provided for detecting viable bacteria in a suspension sample. A sample of a suspension in which bacterial presence is suspected is collected from a source and a portion of the sample transferred to a microfluidic unit. A series of analysis signals at different frequencies are applied to the sample portion. An impedance is measured via a signal analyzer for the sample portion for each of the analysis signals to define an impedance data set. An initial bulk capacitance value is determined for a model circuit based on the impedance dataset. After a predetermined time period, a new bulk capacitance value is determined for on another portion of the sample. The difference between the new bulk capacitance and the initial bulk capacitance value is compared to a threshold value to determine if viable bacterial is present in the sample.

Abstract: A multiple flow system and method for detecting substances in a fluid is provided. More specifically, a first fluid tube containing a first fluid and a second fluid tube containing a second fluid are coupled to a common fluid tube via a connector, such that alternating discrete compartments of the first fluid and the second fluid flow through the common fluid tube. The first and second fluids are immiscible. A substance detector, having a flow chamber with an internal wall, is coupled to the common fluid tube. The alternating discrete compartments of the first and second fluids flow through the flow chamber and are analyzed by the substance detector.

Abstract: An improved system and method is provided for detecting viable bacteria in a suspension sample. A sample of a suspension in which bacterial presence is suspected is collected from a source and a portion of the sample transferred to a microfluidic unit. A series of analysis signals at different frequencies are applied to the sample portion. An impedance is measured via a signal analyzer for the sample portion for each of the analysis signals to define an impedance data set. An initial bulk capacitance value is determined for a model circuit based on the impedance dataset. After a predetermined time period, a new bulk capacitance value is determined for on another portion of the sample. The difference between the new bulk capacitance and the initial bulk capacitance value is compared to a threshold value to determine if viable bacterial is present in the sample.

Abstract: An electrophoresis device is disclosed which separates cells, particles, proteins and other separands by collecting samples of decreasing electrophoretic mobility in a train of inverted cavities while an electric field is applied between said inverted cavities and one or more sample cuvettes containing a mixture of cells, particles, proteins or other separands. One circular plate is provided for the one or more sample cuvettes, and one circular plate is provided for the multiple collection cavities. The invention utilizes an innovative purification method that combines free electrophoresis and multistage extraction in an instrument capable of separating living cells, particles, and proteins in useful quantities at high concentrations. The purification method includes a method for dealing with electrolysis products, a technique for controlling the electrical energy input, and an approach for keeping the process isothermal.

Abstract: An electrophoresis device is disclosed which separates cells, particles, proteins and other separands by collecting samples of decreasing electrophoretic mobility in a train of inverted cavities while an electric field is applied between said inverted cavities and one or more sample cuvettes containing a mixture of cells, particles, proteins or other separands. One circular plate is provided for the one or more sample cuvettes, and one circular plate is provided for the multiple collection cavities. The invention utilizes an innovative purification method that combines free electrophoresis and multistage extraction in an instrument capable of separating living cells, particles, and proteins in useful quantities at high concentrations. The purification method includes a method for dealing with electrolysis products, a technique for controlling the electrical energy input, and an approach for keeping the process isothermal.