Biomedical subjects

Jürgen Wolfgang

Publications and source records attributed to Jürgen Wolfgang.

3 recordsLinked to original sources

PubMed2002

Fiber optic multi-channel protein detector for use in preparative continuous annular chromatography.

Continuous annular chromatography is an effective method in the separation of preparative scale quantities of biological compounds including proteins where established batch chromatography borders on it. The need for identification or quantification of proteins triggered the development of respective detection units. Here, we describe two types of optical multi-channel detectors. The first is a fiber optic multi-channel detector suitable for the separation of aqueous protein solutions. The second is a technically improved (circular optic) device suitable for application in multi-channel detection. Specifically, UV-absorption measurements of proteins at 280 nm were carried out using newly designed fiber optic detectors having eight and 16 channels. Calibration plots were established for a series of stock solutions of known concentrations of proteins. Mathematical functions were derived from these calibration data to simulate the response of the detector. Limits of detection and the ranges of validity of the fit functions were determined. The 16-channel detector has a theoretical limit of detection that is equivalent to absorbance changes of 10(-4) units.

Chromatography, Liquid↗

PubMed2002

Preparative continuous annular chromatography (P-CAC) enables the large-scale fractionation of fructans.

Fructans (fructo-oligosaccharides and inulin) are of increasing physiological and nutritional interest due to their health-promoting effects. Fructans originally extracted from chicory roots were separated by continuous annular and fixed-bed conventional gel chromatography. Both columns were packed with Toyopearl HW 40 (S) and eluted with deionized water. A multicomponent fractionation was established to obtain single oligosaccharides in a low molecular weight range up to a chain length of five and fractions containing an overall size distribution in the high molecular weight range up to a chain length of 90 monosaccharide units. The productivity and resolution of the continuous annular size exclusion chromatograph (40 cm bed height) were investigated and compared with those of the fixed-bed counterpart (2 x 100 cm bed height). The eluting fractions were analyzed by high-pH anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The productivity of the annular system was found to be 25-fold higher than the conventional system. Thus, annular chromatography exemplified for the fractionation of fructans is a powerful method for the large-scale and continuous fractionation of oligomeric and polymeric carbohydrates.

Chemical Fractionation↗

PubMed2002

Continuous annular chromatography.

In recent years the demand for process scale chromatography systems in the industrial downstream process has been increasing steadily. Chromatography seems to be the method of choice when biological active compounds must be recovered from a mixture containing dozens of side products and contaminants as it is for example the case when processing fermentation broths. Since chromatography can solve almost any separation problem under mild operating conditions, a continuous chromatography system represents an extremely attractive and powerful option for such large-scale applications. The increasing number of biotechnological products forces system suppliers of the downstream processing side to develop new and improved high throughput purification technologies. Continuous Annular Chromatography (CAC) has been shown to be the only continuous chromatography technique to fulfill the high demands raised by modern biotechnological productions. In recent years Prior Separation Technology has transferred the principle of Continuous annular chromatography from the research laboratories to the fully developed industrial downstream process scale. The technology is now called Preparative Continuous Annular Chromatography--P-CAC. It can be placed at any stage in the downstream line starting at the very early stages where capturing and concentration of the desired product is required down to the polishing steps, which assure a sufficient final purity of the end product.

Biotechnology↗