An In-House Built Semiautomated Countercurrent Chromatography Workstation

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.