The present invention relates to a method of measuring at least one product quality attributes, including critical quality attributes (e.g., oxidation, C-terminal lysine, aggregation, N-terminal glutamine cyclization.) by an online liquid chromatography system, wherein the liquid chromatography system is running a hydrophobic interaction chromatography (HIC) method.

A plug unit configured for use in high performance liquid chromatography is described. The plug unit comprises a capillary comprising a capillary distal face; a sealing element, wherein at least a portion of the sealing element is located distal from the capillary distal face; and a biasing element configured to bias the capillary towards the sealing element.

Described is a radial flow column for conveying a liquid product through an adsorber material, more particularly for radial flow chromatography, having a housing and, arranged therein, an inner and an outer screen, each of which surrounds a longitudinal axis of the housing and between which a radial intermediate space for receiving the adsorber material is formed. The end-face end regions of the inner and outer screen are sealed with respect to the housing in order to convey the product radially through the screens and the adsorber material. Because the radial flow column comprises ring seals for radially sealing the end-face end regions and the ring seals with corresponding sealing faces permit an axial play of the screens in the housing, production tolerances of the screens with respect to one another and in relation to the housing, and longitudinal fluctuations of the screens, can be compensated in a material-preserving manner.

Provided herein are methods for determining the serotype of a virus particle and/or or determining the heterogeneity of a virus particle (e.g., an AAV particle). In other embodiments, the invention provides methods to determine the heterogeneity of AAV particles. In some aspects, the invention provides viral particles (e.g., rAAV particles) with improved stability and/or improved transduction efficiency by increasing the acetylation and/or deamidation of capsid proteins.

Disclosed herein are systems for imaging and ablating a sample. An imaging/ablating device includes an optical assembly, a sample stage, and a receiver. The optical assembly enables ablation of a region of interest within the sample. The laser light propagated from the optical assembly during ablation propagates substantially in the same direction as the direction of travel of the ablation plume toward the receiver. A laser focus detection unit including at least one reference laser and photodetector generates at least one real-time detection signal indicative of one or more characteristics of the sample during ablation and/or of a distance from the objective to the sample stage or a surface of the sample. A controller coupled with the laser focus detection unit dynamically controls in real-time one or more parameters of the ablation laser and/or a position of the objective and/or a position of the receiver relative to the sample to improve MS imaging quality.

This disclosure provides liquid chromatography tandem mass spectrometer (LC-MS/MS) methods and systems for detecting low levels of pesticides in a test sample. In the disclosed methods and systems, an ammonium salt is added to a mobile phase added to a liquid chromatography column or to the eluant from a liquid chromatography column. This addition improves the signal for certain pesticides by a factor of from 2 to 20, improving their detection limits in a variety of test samples.

The present disclosure discusses a method of separating and/or purifying acidic peptides by the use of a mobile phase having a pH greater than or about equal to the isoelectric point of one or more of the metal oxides in the flow path.

Disclosed are chromatography systems employing a releasable coupling (100) for holding a fluid tubing to a spigot, the coupling comprising: a cylindrical inner component (110) for accepting a fluid tubing (30), said inner component including a resiliently deflectable portion (118) arranged to urge an outer surface of the tubing toward a spigot; and a cylindrical collar (130) having and internal through-aperture (132) for slideably accepting the inner component, the aperture and resilient portion having complementary surface formations which in a first position of the collar mounted to the inner component provide for said resilient deflection in use, and which in a second different position do not cause said deflection, the coupling being characterized in that the collar comprises a collar flange (134) extending outwardly away from the aperture of a size allowing manual manipulation of the collar between the first and second positions. Chromatography systems employing said couplings is disclosed also.

A mode of a chromatograph mass spectrometer configured to collect chromatograph mass spectrometry data by repeatedly performing MS analysis and MS/MS analysis or only MS/MS analysis according to a predetermined condition in the mass spectrometer unit on a sample containing a compound separated by a chromatograph unit; a scatter diagram creation section (45) configured to create, based on the data collected by the measurement unit, a scatter diagram in which a retention time and a mass-to-charge ratio of precursor ions are set to axes orthogonal to each other and positions or ranges of the precursor ions from which MS/MS spectra are acquired are plotted; a spectrum creation unit (46) configured to create MS/MS spectra corresponding to the precursor ions indicated on the scatter diagram; and a display processing unit (48) configured to display the scatter diagram and the MS/MS spectra together on a screen of a display unit.

An analysis method is provided, wherein a measurement sample containing a diamine and an acid dianhydride can be obtained without a separate methyl derivatization process. The analysis method includes pretreating a polyimide film including the polyimide which is a poorly soluble polymer with DMAc after hydrolysis, and determining an amount of monomers contained in the polyimide film.