Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.

Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.

Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.

Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.

Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.

Described herein is a method of analyzing nutrient content in soil, the method comprising a) obtaining a soil sample, b) adding a liquid to the soil sample to form a soil slurry, c) flowing the soil slurry through a filter, whereby the filter is oriented such that the soil slurry flows downward through the filter at least partially under the effects of gravity, d) blending a reagent composition with the soil slurry to form a soil mixture, and e) measuring an absorbance of the soil mixture.

An embodiment includes a sample receiving region, a first diagnostic element that includes one or more colorimetric analysis regions, and a second diagnostic element that includes one or more lateral flow assay analysis regions. The embodiment also includes a first flow path that allows a portion of a liquid deposited at the sample receiving region to flow to the first diagnostic element. The embodiment also includes a second flow path that allows a portion of the liquid deposited at the sample receiving region to flow to the second diagnostic element.

There is provided a method for measuring an antigen, comprising: providing a solution containing an antigen; providing a first antibody that specifically recognizes the antigen and is bound to a magnetic carrier; providing a second antibody that specifically recognizes the antigen and is modified with an oxidase; providing (a substrate liquid including) a substrate which reacts with the oxidase; allowing the first antibody to recognize the antigen; allowing the second antibody to recognize the antigen; using a magnetic field to capture an antigen-antibody complex of the antigen recognized by the first antibody and the second antibody in the magnetic field; washing the antigen-antibody complex while it is captured in the magnetic field; reacting the substrate with the antigen-antibody complex to produce hydrogen peroxide; and measuring the hydrogen peroxide.

A plasmon resonance system, instrument, cartridge, and methods for analysis of analytes is disclosed. A PR system is provided that may include a DMF-LSPR cartridge that may support both digital microfluidic (DMF) capability and localized surface plasmon resonance (LSPR) capability for analysis of analytes. In some examples, the DMF portion of the DMF-LSPR cartridge may include an electrode arrangement for performing droplet operations, whereas the LSPR portion of the DMF-LSPR cartridge may include an LSPR sensor. In other examples, the LSPR portion of the DMF-LSPR cartridge may include an in-line reference channel, wherein the in-line reference channel may be a fluid channel including at least one functionalized LSPR sensor (or sample spot) and at least one non-functionalized LSPR sensor (or reference spot). Additionally, methods of using the PR system for analysis of analytes are provided.

A sensor component for use in a system for measuring concentration of analytes in fluid in a fluid line comprises one or more sensing elements having an optical property that varies with the concentration of the analytes, and engages with the fluid line such that the sensing elements are exposed to the fluid. The sensor component comprises a connector connecting to one or more optical waveguides, and transmits light between the waveguides and the sensing elements. The sensor component comprises one or more of a sampling port configured to provide fluidic access to the fluid line, a data storage medium storing data representing information about the sensor component, and a reflective element. Where it comprises a reflective element, the sensor component transmits light between the waveguides and the reflective element on a separate optical path from an optical path between the waveguides and the sensing elements.