Rapid online proteolytic mapping of PEGylated rhGH for identity confirmation, quantitation of methionine oxidation and quantitation of UnPEGylated N-terminus using HPLC with UV detection.

Proteolytic mapping is a widely used tool in the BioPharmaceutical Industry for the analysis of post-translation modifications as well as confirmation of protein identity by comparison to a well-characterized reference standard. This manuscript presents an integrated chromatographic approach which provides the ability to rapidly digest and analyze a PEGylated rhGH for methionine oxidation, identity confirmation and free (unPEGylated) N-terminal peptide by RP-HPLC using UV detection at 280 nm. This approach utilizes an online procedure in which the digestion step is integrated to the RP-HPLC analysis via an external column switching valve.

High binding capacity surface grafted monolithic columns for cation exchange chromatography of proteins and peptides.

Poly(glycidyl methacrylate-co-ethylene methacrylate) monoliths have been prepared in 100 microm i.d. capillaries and their epoxy groups hydrolyzed to obtain poly(2,3-dihydroxypropyl methacrylate-co-ethylene methacrylate) matrix.

Impact of epidermal leaf mining by the aspen leaf miner (Phyllocnistis populiella) on the growth, physiology, and leaf longevity of quaking aspen.

The aspen leaf miner, Phyllocnistis populiella, feeds on the contents of epidermal cells on both top (adaxial) and bottom (abaxial) surfaces of quaking aspen leaves, leaving the photosynthetic tissue of the mesophyll intact. This type of feeding is taxonomically restricted to a small subset of leaf mining insects but can cause widespread plant damage during outbreaks. We studied the effect of epidermal mining on aspen growth and physiology during an outbreak of P.

The alpha-tocopherol content of leaves of pedunculate oak (Quercus robur L.)--variation over the growing season and along the vertical light gradient in the canopy.

This study was performed in order to investigate whether the actual requirement for defence against photo-oxidative stress is reflected by the alpha-tocopherol (alpha-Toco) content in leaves of pedunculate oak (Quercus robur L.). Antioxidants and pigments were quantified in leaves that were collected on six days between May and September 2000 in a mixed pine/oak forest at canopy positions differing in light environment.

Rapid CE microbial assays for consumer products that contain active bacteria.

Recent advances in high efficiency separation methods of bacteria allow their rapid identification and quantitation in some cases. A specific capillary electrophoresis (CE) technique is used to identify and quantitate Lactobacillus acidophilus in both pill and syrup health products as well as Bifidobacterium infantis in a powdered formula supplement. Cell viability can be evaluated as well.

Rapid identification of the bacterial pathogens responsible for urinary tract infections using direct injection CE.

The use of high-performance capillary electrokinetic techniques for the separation, identification, and quantitation of intact microbes represents a new frontier for separation science. In this work, it is demonstrated that pathogens most responsible for urinary tract infections can be distinguished from one another after direct injection of untreated urine. High efficiencies (often exceeding 1000000 plates/m) and short analysis times (< 10 min) are characteristics of this approach.

High efficiency separation of microbial aggregates using capillary electrophoresis.

Recent advances in the technique of capillary electrophoresis have demonstrated fast, highly efficient separation of mixtures of intact microbes. This paper describes the application of this technique for the separation of microbial aggregates of Micrococcus luteus, Saccharomyces cerevisiae, or Alcaligenes faecalis. The aggregates of these microbes were resolved into several highly efficient peaks with analysis times under 10 min and efficiencies approaching 1000000 plates m(-1) in some cases.

Separating microbes in the manner of molecules. 1. Capillary electrokinetic approaches.

Selective, high-efficiency separations of intact bacteria may, in some cases, allow them to be identified and quantified in much the same way that molecules are done today. Two different capillary electrokinetic approaches were utilized. The first approach used a dissolved polymer-based CE separation that may be affected by size and shape considerations.

Avoparcin, a new macrocyclic antibiotic chiral run buffer additive for capillary electrophoresis.

Avoparcin, like vancomycin, teicoplanin, and ristocetin A, belongs to the family of macrocyclic glycopeptide antibiotics. These antibiotics have all been used as effective chiral selectors for capillary electrophoresis (CE), thin-layer chromatography (TLC), and high performance liquid chromatography (HPLC). The present work focuses on avoparcin, which has been shown to be an excellent chiral selector for the CE enantioseparation of many N-blocked amino acids, as well as several anti-inflammatory drugs of pharmaceutical importance.

Plant and soil enantioselective biodegradation of racemic phenoxyalkanoic herbicides.

The biodegradation of the chiral phenoxyalkanoic herbicides 2-(2,4-dichlorophenoxy)propionic aid (2,4-DP) and 2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) was investigated using enantioselective HPLC and chiroptical detection. Racemic mixtures of 2,4-DP and MCPP were applied to three species of turf grass, four species of broadleaf weeds, and soil. Preferential degradation of the S-(-) enantiomer of each herbicide was observed in most species of broadleaf weeds and soil, while the degradation in all species of grass occurred without enantioselectivity.

Bubble fractionation of enantiomers from solution using molecularly imprinted polymers as collectors.

Adsorptive bubble separation methods have been used to enrich components from both heterogeneous and homogeneous solutions. These methods are particularly effective for processing large solution volumes at low cost. Previous work demonstrated that chiral, surface-active collectors could be used to enrich enantiomers from homogeneous solution in a foam fractionation process.

Selective in vivo and in vitro sampling of proteins using miniature ultrafiltration sampling probes.

The most widely used in vivo sampling technique, microdialysis sampling, provides important data on the extracellular concentration of low molecular mass (<1000-5000 Da) species. However, biological macromolecules of much greater mass (>20-90 kDa) have key in vivo roles as chemical messengers or are currently under consideration as biopharmaceuticals. Microdialysis, which utilizes a sampling process based upon analyte diffusion, is largely ineffective at monitoring the local, transient extracellular concentrations of important macromolecular species.