To develop pharmaceutical treatments for obesity and diabetes, researchers carry out food intake studies and more in-depth assessments of the feeding behavior in rodents. To facilitate such studies, the authors designed and developed a rodent behavior monitoring system that simultaneously measures food intake, water consumption and motor activity. When tested, their Automated Water Food Activity System (AWFAS) substantially increased throughput for routine rat food intake studies and also improved user ergonomics and safety. The authors describe their system and suggest that others could design similar systems or adapt certain features of the AWFAS to fit existing rodent caging systems.

An elution—extrusion countercurrent chromatography workstation was designed and built in-house for fractionating crude natural product extracts. The engineering efforts of this project included both custom hardware and software integration. The resulting workstation operates four individual chromatography coils for natural product extract separation and purification. The workstation offers the ability to collect fractions into 16 × 100 mm borosilicate glass test tubes or allows for stream splitting of the coil effluent so that the fractions can be collected into both 16 × 100 mm borosilicate test tubes and a 96-well microplate. Solvent pumping for each of the chromatography columns is achieved through the use of syringe pumps. The workstation is controlled though a custom control software application, C_Cubed, written in Visual Basic 6.0 (VB6). Software architecture consists of three levels. At the lowest level, there are ActiveX dll device drivers that interface with the physical hardware. The middle layer is a custom scheduler allowing for multitasking of instrument movements. The upper level is composed of a Wizard-style user interface that mimics the scientific workflow. Finally, by using a software timer the software application was written to operate on a single thread, but exhibit multithreaded behavior.

A tool for improved tandem column chiral supercritical fluid chromatography (SFC) method development screening was prepared by modification of a commercial analytical SFC instrument with two different software-controllable, six position high-pressure column selection valves, each controlling a bank of five different columns and a pass through line. The resulting instrument, which has the ability to screen 10 different individual columns and 25 different tandem column arrangements, is a useful tool for facilitating the screening of tandem column SFC arrangements for separation of complex mixtures of stereoisomers or other multicomponent mixtures. Strategies for optimal use of the instrument are discussed, and several examples of the use of the instrument in developing tandem SFC methods for resolution of multicomponent mixtures are presented.

Constantly improving biological assay development continues to drive technological requirements. Recently, a specification was defined for capturing white light and fluorescent images of agar plates ranging in size from the NUNC Omni tray (96-well footprint, 128 x 85 mm) to the NUNC BioAssay Dish (245 x 245 mm). An evaluation of commercially available products failed to identify any system capable of fluorescent macroimaging with discrete wavelength selection. To address the lack of a commercially available system, a custom imaging system was designed and constructed. This system provides the same capabilities of many commercially available systems with the added ability to fluorescently image up to a 245 x 245 mm area using wavelengths in the visible light spectrum.

Utilizing flow cytometry, we previously demonstrated that the potassium channel blocker margatoxin (MgTX) inhibits the [Ca2+]i transient involved in T-cell activation. We wished to extend these studies to single-cell transients using florescence digital-imaging microscopy (DIM). However, the most currently available temperature-regulation chambers reuse part or all of the apparatus and introduce compounds via perfusion. Thus, these apparatuses are not suitable for studies involving compounds that are particularly sticky. We have designed a dual-temperature regulation system that will maintain Nunc, eight-well, coverglass-bottom, disposable chambers, and three disposable addition pipets at 37 degrees C for physiological studies on an inverted digital-imaging microscope. We have demonstrated that calcium transients of human T lymphocytes can be initiated and monitored reproducibly during the addition of three distinct chemical species. The DIM results correlate with flow cytometry measurements in the number of responding cells and the heterogeneity of the response in both control and MgTX-inhibited cultures. Additionally, DIM revealed that the [Ca2+]i transient is more rapid than the flow-cytometric measurement indicated. The correlation between flow cytometry and DIM permits the amalgamation of these results in the interpretation of studies on the regulation of T-cell activation.