The biopharmaceutical industry characterizes and quantifies aggregation of protein therapeutics using multiple analytical techniques to cross-validate results. Here, we demonstrate the use of electrospray-differential mobility analysis (ES-DMA), a gas-phase and atmospheric pressure ion-mobility method for characterizing protein aggregates. Two immunoglobulin Gs are systematically heat treated t...

Abstract Hydrolysis of cellulose in concentrated phosphoric acid is known to give two distinctive mono-disperse cello-oligomers: the degree polymerization (DP) 7 and 15. To understand formation mechanism monodisperse cello-oligomers, transition DP during hydrolysis was monitored by size-exclusion chromatography combined with multiangle laser-light scattering analyses (SEC/MALLS). The obtained r...

The high-temperature gas chromatographic (GC) separation of several semivolatile compounds is studied with a short metal capillary column packed with fibrous material, having a polydimethylsiloxane coating thereon. Taking advantage of the excellent heat-resistance of the fiber and also the combination of the surface-deactivated metal capillary, a temperature-programmed separation up to 450 degr...

Separation of macromolecules on the basis of their molecular weight by size exclusion chromatography has long been considered to be caused by the geometry-dependent partition of macromolecules between a continuous phase and the porous interior of a gel or cross-linked bead. The volume of a pore accessible to a solute is limited by its relative dimensions, so larger molecules will have access to...

Anatase TiO2 nanoparticles with a mean diameter of approximately 10 nm were successfully synthesized by a nonaqueous sol-gel route without the use of air-free equipment. The nanoparticles are well dispersed in common organic solvents in the form of primary particles, and the colloid is stable for more than one year. The particles and colloid were studied by X-ray diffraction (XRD), transmission...

Heparin is widely used as an anticoagulant for the treatment and prevention of various thrombotic diseases. However, due to its high anionic charge, heterogeneity in size distribution and high polarity, its analysis is very challenging. In this paper, a novel method based on size-exclusion chromatography (SEC) for quantitative determination of intact heparin in pharmaceuticals is presented. Ana...

A two-dimensional liquid chromatographic system is described here which uses size-exclusion liquid chromatography (SEC) followed by reversed-phase liquid chromatography (RPLC) to separate the mixture of proteins resulting from the lysis of Escherichia coli cells and to isolate the proteins that they produce. The size-exclusion chromatography can be conducted under either denaturing or nondenatu...

The shortening of the 3'-end poly(A) tail, also called deadenylation, is crucial to the regulation of mRNA processing, transportation, translation and degradation. The deadenylation process is achieved by deadenylases, which specifically catalyze the removal of the poly(A) tail at the 3'-end of eukaryotic mRNAs and release 5'-AMP as the product. To achieve their physiological functions, all dea...