The invention generally relates to systems and methods for quantifying an analyte extracted from a sample. In certain embodiments, the invention provides methods that involve introducing a solvent into a capillary, introducing the capillary into a vessel including a sample such that a portion of the sample is introduced into the capillary, moving the sample and the solvent within the capillary to induce circulation within the sample and the solvent, thereby causing the analyte to be extracted from the sample and into the solvent, analyzing the analyte that has been extracted from the sample, and quantifying the analyte. In certain embodiments, the quantifying step is performed without knowledge of a volume of the sample and/or solvent.

Cartridges for the isolation of a biological sample and downstream biological assays on the sample are provided, as are methods for using such cartridges. In one embodiment, a nucleic acid sample is isolated from a biological sample and the nucleic acid sample is amplified, for example by the polymerase chain reaction. The cartridges provided herein can also be used for the isolation of non-nucleic acid samples, for example proteins, and to perform downstream reactions on the proteins, for example, binding assays. Instruments for carrying out the downstream biological assays and for detecting the results of the assays are also provided.

Microfluidic devices, assemblies, and systems are provided, as are methods of manipulating micro-sized samples of fluids. Microfluidic devices having a plurality of specialized processing features are also provided.

Methods, devices and systems for capturing biomarkers are provided. In particular, methods, compositions, and systems that utilize affinity capture devices comprising a processing chamber, affinity capture agent and porous membrane are provided.

Disclosed is a method for detecting the presence of a type I pyrethroid in an object including the steps of (a) contacting the object with a solvent and an absorbent substrate, (b) separating the absorbent substrate from the object, (c) evaporating the solvent from the absorbent substrate, (d) treating the absorbent substrate with a solution comprising a nitrite salt in concentrated sulfuric acid, and (e) observing the absorbent substrate for a color change indicating the presence of the type I pyrethroid in the object. The invention also provides a kit for detecting the presence of the type I pyrethroid in an object.

A method of determining beryllium or a beryllium compound thereof in a sample is disclosed by measuring fluorescence. This method discloses use of highly alkaline fluorescent indicating dye solutions with pH greater than 12.9. In a preferred embodiment the fluorescent indicating dye solutions do not contain a pH buffer. 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, preferably 12. The use of highly alkaline solution provides superior detection limits for beryllium by using dilution ratios of 4 and lower.

The invention relates to the detection of DHA and EPA. In a particular aspect, the invention relates to methods for detecting DHA and EPA by mass spectrometry and kits for carrying out such methods.

A fluid control and processing system for controlling fluid flow among a plurality of chambers comprises a body including a fluid processing region continuously coupled fluidicly with a fluid displacement region. The fluid displacement region is depressurizable to draw fluid into the fluid displacement region and pressurizable to expel fluid from the fluid displacement region. The body includes at least one external port. The fluid processing region is fluidicly coupled with the at least one external port. The fluid displacement region is fluidicly coupled with at least one external port of the body. The body is adjustable with respect to the plurality of chambers to place the at least one external port selectively in fluidic communication with the plurality of chambers. One or more of the chambers may be a processing chamber which includes two ports configured to selectively engage the at least one external port of the body, and a fluid processing material such as an enrichment material or a depletion material. In some embodiments, one or more chambers may include a separation channel, and an electric field may be applied across the separation channel.

A sampling device is provided for concentrating a liquid specimen sample, including a filtration assembly, which includes a tubular container and a plunger. The plunger includes a plunger head and a plunger rod that is shaped so as to define an internal plunger space having a plunger-space proximal opening through a proximal end of the plunger rod. The sampling device is configured such that a filter is removable from the tubular container via the plunger-space proximal opening while the plunger head is within the tubular container. Other embodiments are also described.

Sampling devices for mercury speciation protocols are described. Devices can be utilized to separate mercury species from one another as a sample diffuses through a sampling device. Methods can determine the presence or quantity of targeted mercury species in a fluid sample. The devices are passive sampling devices based upon diffusion gradient in thin film (DGT) passive sampling devices. Devices include a reactant component and a sequesterant component that selectively react with a targeted species and retain a species (or a reaction product of a species) of a sample flow. Remaining mercury species can optionally be captured downgradient, for instance at an ion exchange resin.