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Inductively coupled plasma mass spectrometry (ICP-MS) has been applied for the analysis of biomolecules due to its high sensitivity, wide linear dynamic range, and multielement capabilities. However, outside the elemental MS community the potential of this technique, e.g. for life sciences applications, is not yet fully exploited. Thus, the development of ICP-MS-based (immuno) assays for a wide range of medical (cancer diagnostics, cisplatin toxicity studies), biochemical (DNA microarray, single cell analysis), and environmental (analysis of comestible goods) applications was accomplished by utilization of chemical labels. Laser ablation (LA)-ICP-MS was employed for the direct analysis of solid samples like microarrays and thin tissue sections. An immunoassay was developed for ochratoxin A (OTA) determination in wine, and ICP-MS detection was compared to conventional photometry by gold nanoparticle tagging and horseradish peroxidase, respectively. Detection limits of the assay were optimized to 0.003 μg L-1, and the quantification range was 0.01–1 μg L-1 for both methods. For LA-ICP-MS-based DNA microarray detection, gold nanoparticle tags were specifically introduced via a streptavidin-biotin linkage. In immunohistochemistry (IHC), up to 20 tumor markers are routinely evaluated for one patient and thus, a common analysis results in a series of time consuming staining procedures. Hence, LA-ICP- MS was elaborated as a detection tool for a novel, multiplexed IHC analysis of tissue sections. Different lanthanides were employed for the simultaneous detection of up to three tumor markers (Her 2, CK 7, and MUC 1) in a breast cancer tissue. Additionally, iodine was employed as a labeling reagent, and a new LA-ICP-MS method for single cell and cell nucleus imaging was developed at 4 μm laser spot size. Iodine was also applied as a new internal standard for tissue samples. Moreover, Pt-protein complexes separated by an optimized 1D and 2D gel electrophoresis were analyzed by LA-ICP-MS. The high spatial resolution of this technique was further demonstrated in a current study of cisplatin toxicity and renal protective strategies in rat kidney tissue by detecting platinated proteins.
The aim of this work was the preparation of a novel stationary monolithic phase for affinity chromatography and HPLC-applications. Therefore, we have chosen porous glass filters that are available with different pore sizes as raw materials to prepare monolithic columns. We purchased VitraPOR 4 (10-16 μm pore size) and VitraPOR 5 (1.0-1.6 μm pore size) monolithic glass filters. The physical properties of these glass filters were characterized. The surface area, pore size distribution and the porosity were determined using mercury intrusion porosimetry and BET. These glass filters only exhibit flow through pores and therefore show no bimodal pore size distribution in the mercury intrusion curves. Due to their low permeability, the applied filters that exhibit an inner diameter of 8.0 mm and a length of 15.0±0.1 mm could be operated at flow rates more than 10 ml/min. High flow rates are favorable for fast separation experiments.