The disclosure provides a reagent for extracting immunosuppressant drugs from whole blood sample for immunoassay. The extraction reagent comprises protein denaturant, proteolytic enzyme, surfactant and pH buffer. The disclosure also provides a method and an immunoassay kit for detection of the immunosuppressant concentration in a whole blood sample using the extraction reagent. The extraction reagent of the present disclosure doesn't need the use of organic solvent as that in the traditional extraction method, therefore the adverse effects of the organic solvent on the antibody activity in a detection system and the other relative defects associated to its use are obviated. The drug extraction process of the present disclosure doesn't need centrifugation, the processed sample can be directly applied for immunoassay. The operation for drug extraction by the present disclosure is simple, and the detection result based on this extraction method is accurate.

A method of determining beryllium or a beryllium compound thereof in a sample is disclosed by measuring fluorescence. This method discloses use of highly strong acids to extract beryllium from samples into the said acidic medium, and then using these solutions in combination with alkaline fluorescent indicating dye solutions to determine the amount of beryllium in the said samples. Further, the method also discloses measuring fluorescence under highly alkaline conditions, where the pH after mixing the highly alkaline fluorescent indicating dye solutions with the sample solution containing beryllium is at least 11.3.

A method of marking a hydrated tissue specimen for mechanical testing is provided. The method includes adding a metal nanoparticle precursor solution to a reducing agent solution to form a mixture; incubating the mixture to form a plurality of aggregated metal nanoparticles, where each of the aggregated metal nanoparticles includes a plurality of individual metal nanoparticles; separating the plurality of aggregated metal nanoparticles from a supernatant by means of centrifugation or gravitational settling; resuspending the plurality of aggregated metal nanoparticles in a buffer solution to form a colloidal metal nanoparticle suspension; and soaking the hydrated tissue specimen in the colloidal metal nanoparticle suspension, where at least a portion of the plurality of aggregated metal nanoparticles adhere to the hydrated tissue specimen in a random pattern of speckles.

Microfluidic devices and nanobiosensors comprising a magnetic nanoparticle attached to a reporter molecule via a release unit for microfluidic-based detection of a target analyte in a biological sample. The nanobiosensor can be magnetically manipulated or guided through the microfluidics channels for incubation with the biological sample, concentration of the nanobiosensors, and detection of target analytes, without having to pump the entire initial sample through the microfluidic channel. The magnetic nanoparticles are separated from the reporter molecules before detection and can be re-used.

The disclosure provides methods of forming one or more single-cell proteomic samples, such as by: dispensing n droplets of lysis buffer onto a substantially planar solid surface, wherein n>2: dispensing a single cell into each of the n droplets of lysis buffer to produce n droplets with a lysed single cell: dispensing digestion buffer into each of the n droplets to digest proteins from each lysed single cell to produce n droplets comprising peptides: dispensing a chemical tag into at least a subset of the n droplets comprising the peptides to produce labeled peptides, thereby enabling the labeled peptides in a given droplet to be distinguishable from labeled peptides in at least one other droplet: and applying a fluid to merge at least a subset of the droplets into a combined droplet on the substantially planar surface, thereby combining the labeled peptides to form a single-cell proteomic sample.

The exemplary system and method configured to perform benthic flux incubation and measurement in an on-going continuous manner via motorized or non-motorized actuators that moves one or more sampling chambers (i) between different sampling regions or (ii) maintains the sampling chamber over a single region, for long term repeated measurements. The exemplary system and method can incubate and sample over multiple benthic sampling regions to acquire repeated measurements of both (i) fluxes and (ii) background processes and conditions (e.g., via ambient water incubations or ambient water concentration measurements), the results of which can be combined and processed by the exemplary system to generate data requiring minimal post-processing.

Oil-based drilling fluids can include an emulsifier to help stabilize the phases of the fluid. During repeated use, the amount of free emulsifier can become depleted. A field test can be used to determine the amount of free emulsifier in the fluid. Top oil from an aliquot from the fluid can be placed into a testing vial and mixed with an aqueous solution including a dye and optionally a pH adjuster or an acid or acidic buffer to facilitate dye transfer from the aqueous phase to the oil phase. The amount of dye transferred to the oil phase can be used to determine the amount of free emulsifier. Reference samples can be prepared with a known concentration of the emulsifier to visually compare the amount of dye transfer in the testing vial to the reference sample. Spectroscopy can also be used to compare the dye transfer in the test vial to the reference sample.

The disclosure provides a reagent for extracting immunosuppressant drugs from whole blood sample for immunoassay. The extraction reagent comprises protein denaturant, proteolytic enzyme, surfactant and pH buffer. The disclosure also provides a method and an immunoassay kit for detection of the immunosuppressant concentration in a whole blood sample using the extraction reagent. The extraction reagent of the present disclosure doesn't need the use of organic solvent as that in the traditional extraction method, therefore the adverse effects of the organic solvent on the antibody activity in a detection system and the other relative defects associated to its use are obviated. The drug extraction process of the present disclosure doesn't need centrifugation, the processed sample can be directly applied for immunoassay. The operation for drug extraction by the present disclosure is simple, and the detection result based on this extraction method is accurate.

The exemplary system and method configured to perform benthic flux incubation and measurement in an on-going continuous manner via motorized or non-motorized actuators that moves one or more sampling chambers (i) between different sampling regions or (ii) maintains the sampling chamber over a single region, for long term repeated measurements. The exemplary system and method can incubate and sample over multiple benthic sampling regions to acquire repeated measurements of both (i) fluxes and (ii) background processes and conditions (e.g., via ambient water incubations or ambient water concentration measurements), the results of which can be combined and processed by the exemplary system to generate data requiring minimal post-processing.