A microfluidic technique for quantification of steroids in core needle biopsies.

Core needle biopsy (CNB) sampling is known to be inexpensive and minimally invasive relative to traditional tissue resectioning. But CNBs are often not used in analytical settings because of the tiny amount of sample and analyte. To address this challenge, we introduce an analytical method capable of multiplexed steroid quantification in CNB samples-those studied here ranged in mass from 2 to 8 mg.

Attractive design: an elution solvent optimization platform for magnetic-bead-based fractionation using digital microfluidics and design of experiments.

There is great interest in the development of integrated tools allowing for miniaturized sample processing, including solid phase extraction (SPE). We introduce a new format for microfluidic SPE relying on C18-functionalized magnetic beads that can be manipulated in droplets in a digital microfluidic platform. This format provides the opportunity to tune the amount (and potentially the type) of stationary phase on-the-fly, and allows the removal of beads after the extraction (to enable other operations in same device-space), maintaining device reconfigurability.

Analysis on the go: quantitation of drugs of abuse in dried urine with digital microfluidics and miniature mass spectrometry.

We report the development of a method coupling microfluidics and a miniature mass spectrometer, applied to quantitation of drugs of abuse in urine. A custom digital microfluidic system was designed to deliver droplets of solvent to dried urine samples and then transport extracted analytes to an array of nanoelectrospray emitters for analysis. Tandem mass spectrometry (MS/MS) detection was performed using a fully autonomous 25 kg instrument.

Multiplexed extraction and quantitative analysis of pharmaceuticals from DBS samples using digital microfluidics.

Background: Dried blood spot (DBS) sampling is emerging as a valuable technique in a variety of fields, including clinical and preclinical testing of pharmaceuticals. Despite this popularity, current DBS sampling and analysis processes remain laborious and time consuming. Digital microfluidics, a microscale liquid-handling technique, characterized by the manipulation of discrete droplets on open electrode arrays, offers a potential solution to these problems.

A digital microfluidic method for dried blood spot analysis.

Blood samples stored as dried blood spots (DBSs) are emerging as a useful sampling and storage vehicle for a wide range of applications. Unfortunately, the surging popularity of DBS samples has not yet been accompanied by an improvement in automated techniques for extraction and analysis. As a first step towards overcoming this challenge, we have developed a prototype microfluidic system for quantification of amino acids in dried blood spots, in which analytes are extracted, mixed with internal standards, derivatized, and reconstituted for analysis by (off-line and in-line) tandem mass spectrometry.

Detection of acute fentanyl exposure in fresh and decomposed skeletal tissues part II: the effect of dose-death interval.

The effects of dose-death interval on the detection of acute fentanyl exposure in fresh and decomposed skeletal tissues (marrow and bone), by automated enzyme-linked immunosorbent assay (ELISA) are described. Rats (n=14) were administered fentanyl acutely at a dose of 0 (n=2) or 60 microg/kg (n=12) by intraperitoneal injection, and euthanized within 20, 45, 135, or 225 min. Femora and tibiae were extracted from the fresh corpses and marrow was isolated from the femoral and tibial medullary cavities.

Detection of acute fentanyl exposure in fresh and decomposed skeletal tissues.

The detection of acute fentanyl exposure in fresh and decomposed skeletal tissues (marrow and bone), by automated enzyme-linked immunosorbent assay (ELISA) is described. Rats (n=15) were administered fentanyl acutely at a dose of 0 (n=3), 15 (n=3), 30 (n=3) or 60 microg/kg (n=6) by intraperitoneal injection, and euthanized within 20 min. Femora and tibiae were extracted from the fresh corpses and marrow was isolated from the femoral and tibial medullary cavities.