Abstract: An assay cartridge for mixing a test sample and reagent for diagnostic purposes, and method of using the same. The assay cartridge includes a housing, an injection port for receiving the test sample (whole blood), a filtration membrane for separating plasma from the sample, a section for receipt of reagent, and one or more sets of valves provided in the housing. Each valve is configured for movement between an open position and a closed position. Metering chambers are provided in the housing for receiving separated plasma and the reagent therein. A port is fluidly connected to each metering chamber and uses to draw air from or deliver pressurized fluid into the housing. Mixing channels are provided in the housing and selectively connected to the metering chambers for mixing the separated plasma and reagent into a substantially homogeneous mixture. The homogeneous mixture is delivered out of the housing through output ports.

Abstract: A method of detecting a metal ion in a protein-containing sample includes adding a protein degrading enzyme to the protein-containing sample to form an enzyme degradation product, adding an acid to the enzyme degradation product to provide a mixture, filtering the mixture to provide a supernatant, extracting the supernatant with an organic solvent to remove organic solvent soluble byproducts to provide a washed aqueous layer, and detecting the metal ion in the washed aqueous layer. The method is amenable to the detection of heavy metal ions in complex products such as milk. A kit includes reagents for performing the method.

Abstract: A method of detecting a metal ion in a protein-containing sample includes adding a protein degrading enzyme to the protein-containing sample to form an enzyme degradation product, adding an acid to the enzyme degradation product to provide a mixture, filtering the mixture to provide a supernatant, extracting the supernatant with an organic solvent to remove organic solvent soluble byproducts to provide a washed aqueous layer, and detecting the metal ion in the washed aqueous layer. The method is amenable to the detection of heavy metal ions in complex products such as milk. A kit includes reagents for performing the method.

Abstract: Methods, systems and programing for substance detection with a magnetic sensor are presented. In one example, a magnetic sensor having one or more layers is formed on a base for sensing a magnetic field created by magnetic particles present in proximity to the magnetic sensor. A first end of each of a first set of strands is immobilized with respect to the magnetic sensor. A magnetic particle is attached to a second end of each of the first set of strands so that when a material containing a substance is in contact with the base, the substance causes at least some of the first set of strands to break resulting in that the magnetic particle attached to the second end of each of the at least some of the first set of strands is no longer in proximity to the magnetic sensor.