Detection of Endotoxins: From Inferring the Responses of Biological Hosts to the Direct Chemical Analysis of Lipopolysaccharides.

A significant portion of the scientific effort has been devoted to the detection of endotoxins in pharmaceutical solutions, as they pose major health threats as contaminants even in minute amounts. Conventional methods based on the biological response of endotoxins have been well-established, but as technology advances, many limitations surfaced in the recent years. As a result, information obtained by chemical analytical methods becomes valuable in crossvalidating these results.

High throughput human plasma N-glycan analysis using DNA analyzer and multivariate analysis for biomarker discovery.

Carbohydrates form the majority of organic compounds found in nature and their presence on proteins influences many important bioactivities. Therefore, glycan profiling shows potential in clinical applications. This work demonstrates the use of a high-throughput GlycanAssure™ sample preparation technology and multi-capillary DNA analyzer for the analysis of the major N-linked glycans (N-glycans) found in human plasma.

Multiplexing N-glycan analysis by DNA analyzer.

Analysis of N-glycan structures has been gaining attentions over the years due to their critical importance to biopharma-based applications and growing roles in biological research. Glycan profiling is also critical to the development of biosimilar drugs. The detailed characterization of N-glycosylation is mandatory because it is a nontemplate driven process and that significantly influences critical properties such as bio-safety and bio-activity.

Parallel analysis and orthogonal identification of N-glycans with different capillary electrophoresis mechanisms.

The deep involvement of glycans or carbohydrate moieties in biological processes makes glycan patterns an important direction for the clinical and medicine researches. A multiplexing CE mapping method for glycan analysis was developed in this study. By applying different CE separation mechanisms, the potential of combined parallel applications of capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC) and capillary gel electrophoresis (CGE) for rapid and accurate identification of glycan was investigated.

Rapid characterization of protein productivity and production stability of CHO cells by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

The biopharmaceutical industry has been in pursuit of strategies which can isolate stable and high-producing cell lines. The whole cell mass spectrometry method by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) is a rapid and simple method for cell characterization based on the differences in the fingerprints of the mass spectra. This work describes how the method was evaluated for the application of screening for stable and high-producing clones from a panel of recombinant Chinese hamster ovary (CHO) cell lines.

Rapid characterization of high/low producer CHO cells using matrix-assisted laser desorption/ionization time-of-flight.

An intact-cell mass spectrometry (ICM) method using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) was evaluated for the screening of stable recombinant Chinese hamster ovary (CHO) cell lines, an important mammalian cell line in bioprocessing. With rapid and simple cell pretreatments, viabilities of cells could be rapidly distinguished on the different fingerprints of mass spectra. Detectable m/z values on cell surfaces and their relative intensities were processed by two biostatistical methods, principle components analysis (PCA) and partial least squares (PLS), with promising results.

Simultaneous determination of 19 intracellular nucleotides and nucleotide sugars in Chinese Hamster ovary cells by capillary electrophoresis.

Twelve nucleotides and seven nucleotide sugars in Chinese Hamster ovary (CHO) cells were determined by capillary electrophoresis (CE). The CE operating conditions of buffer pH value, ion strength, capillary temperature, polymer additive and cell extraction method were investigated. Optimum separation was achieved with 40 mM sodium tetraborate buffer (pH 9.

Immunoassay by capillary electrophoresis with quantum dots.

The application of quantum dots in capillary electrophoresis immunoassay was studied for the first time. Quantum dots were conjugated with antibody and subsequently tested by electrophoretic separation of free antibody and antibody-antigen complex. Antibody was fluorescently labeled by quantum dots via conjugation procedures and its electrophoretic characteristics were effectively modified due to the attachment of quantum dots.

On-chip potential gradient detection with a portable capillary electrophoresis system.

A portable chip-CE system with potential gradient detection (PGD) was developed and applied to the determinations of alkali metals and alkaloids. The separation efficiency appeared to be satisfactory and nonaqueous capillary electrophoresis (NACE) proved to be applicable to PGD or conductivity detection. The power supplies, separation and detection were built on a device of 3 kg in weight.

Analysis of Chinese medicine preparations by capillary electrophoresis-mass spectrometry.

In Chinese medicines, herbs are usually prepared before use by patients. Since the preparation procedures convert the original component into one or more products, study of the procedures is usually complex and involves several compounds. On-line coupling of capillary electrophoresis (CE) to mass spectrometry (MS) allows both the efficient separation of CE and the specific and sensitive detection of MS to be achieved.

Determination of five toxic alkaloids in two common herbal medicines with capillary electrophoresis.

A method was developed for the determination of five highly toxic alkaloids in two commonly used herbal medicines by capillary electrophoresis, which had not been applied to the determination of Aconitum alkaloids before. The buffer contained 40 mM ammonium acetate and 0.1% acetic acid in 80% methanol.