Due to the constant search for reliable methods to investigate glycoproteins in complex biological samples, an alternative approach combining affinity enrichment with rapid and sensitive analysis on-a-chip is presented. Glycoproteins were specifically captured by lectin-coated magnetic beads, eluted by competitive sugars, and investigated with microchip capillary gel electrophoresis (MCGE), i.e.
View Article and Find Full Text PDFLiquid-phase electrophoresis either in the classical capillary format or miniaturized (chip CE) is a valuable tool for quality control of virus preparations and for targeting questions related to conformational changes of viruses during infection. We present an in vitro assay to follow the release of the RNA genome from a human rhinovirus (common cold virus) by using a molecular beacon (MB) and chip CE. The MB, a probe that becomes fluorescent upon hybridization to a complementary sequence, was designed to bind close to the 3' end of the viral genome.
View Article and Find Full Text PDFGlycosylations severely influence a protein's biological and physicochemical properties. Five exemplary proteins with varying glycan moieties were chosen to establish molecular weight (MW) determination (sizing), quantitation, and sensitivity of detection for microchip capillary gel electrophoresis (MCGE). Although sizing showed increasing deviations from literature values (SDS-PAGE or MALDI-MS) with a concomitant higher degree of analyte glycosylation, the reproducibility of MW determination and accuracy of quantitation with high sensitivity and reliability were demonstrated.
View Article and Find Full Text PDFBiodegradable nanoparticles (NPs) and hence e.g. NPs prepared from glutaraldehyde crosslinked gelatin (gelatin NPs) are lately receiving increased attention in various fields like pharmaceutical technology and nutraceutics as biocompatible carriers for hardly water soluble drugs, molecules intended for sustained release or targeted transport.
View Article and Find Full Text PDFBead assays are an emerging microbial detection technology with the capability for rapid detection of extremely low levels of viable pathogens. Such technologies are of high value in clinical settings and in the food industry. Here, we perform a bead assay for extracted 16S rRNA from Escherichia coli (strain K12) with the flow cytometry readout on a 2100 Bioanalyzer, a highly accurate, small-scale flow cytometer system.
View Article and Find Full Text PDFBead assays are an important rapid microbial detection technology suitable for extremely low pathogen levels. We report a bead assay for rRNA extracted from Escherichia coli K12 that does not require amplification steps and has readout on an Agilent 2100 Bioanalyzer flow cytometry system. Our assay was able to detect 125 ng of RNA, which is 16 times less than reported earlier.
View Article and Find Full Text PDFThe molecular weights (MW) of seven (glyco)proteins, of which five were plasma-derived, with MWs higher than 200 kDa were determined with three techniques: CGE-on-a-chip, SDS-PAGE and MALDI-TOF-MS. While the analysis of medium to high MW proteins with SDS-PAGE was an already well-established technique, the usefulness of MALDI-TOF-MS for the exact MW determination of high mass proteins was only partly described in literature so far. CGE-on-a-chip is the newest of all three applied techniques and was so far not applicable.
View Article and Find Full Text PDFBackground: High-density lipoprotein (HDL) subfractions are among the new emerging risk factors for atherosclerosis. In particular, HDL 2b has been shown to be linked to cardiovascular risk. This study uses a novel microfluidics-based method to establish HDL 2b clinical utility using samples from the Prospective Cardiovascular Muenster (PROCAM) Study.
View Article and Find Full Text PDFChanges in chromatin structure, histone phosphorylation and cleavage of DNA into nucleosome-size fragments are characteristic features of apoptosis. Since H1 histones bind to the site of DNA cleavage between nucleosomal cores, the question arises as to whether the state of H1 phosphorylation influences the rate of internucleosomal cleavage. Here, we tested the relation between DNA fragmentation and H1 phosphorylation both in cultured cells and in vitro.
View Article and Find Full Text PDFThe performance of the Agilent 2100 bioanalyzer, the first commercial lab-on-a-chip system, and the Protein 200 Plus LabChip kit is compared with conventional protein analysis techniques such as SDS-PAGE, Lowry, or Bradford. Lab-on-a-chip technology for protein analysis allows for the integration of electrophoretic separation, staining, destaining, and fluorescence detection into a single process, and for it to be combined with data analysis. The chip-based protein assay allows purity analysis, sizing, and relative quantitation based on internal standards or absolute quantitation based on user-defined standards.
View Article and Find Full Text PDF