The present invention provides methods for analyzing compositions of polypeptides such as antibodies by ionic strength-mediated pH gradient ion exchange chromatography. In some aspects, the methods use a combination of pH gradients and ionic strength gradients to separate the polypeptide from charge variants of the polypeptide. In some aspects, the methods use a stable ionic strength to optimize the pH gradient separation window to separate the polypeptide from charge variants. Such methods are useful for analyzing polypeptide, e.g. antibodies, with a pI greater than 9 or a pI less than 7. In some aspects, the invention provides a multiproduct method for the analysis of polypeptides of varying pI's.

The present invention provides methods for analyzing compositions of polypeptides such as antibodies by ionic strength-mediated pH gradient ion exchange chromatography. In some aspects, the methods use a combination of pH gradients and ionic strength gradients to separate the polypeptide from charge variants of the polypeptide. In some aspects, the methods use a stable ionic strength to optimize the pH gradient separation window to separate the polypeptide from charge variants. Such methods are useful for analyzing polypeptide, e.g. antibodies, with a pI greater than 9 or a pI less than 7. In some aspects, the invention provides a multiproduct method for the analysis of polypeptides of varying pI's.

Systems and methods for concentrating an analyte preparatory to analysis thereof include processing the effluent of an analyte concentrator to produce an eluent for eluting an analyte retained in the same or separate concentrator, and systems implementing the same. The analyte concentrator system connects the effluent outlet of an analyte concentrator column to an eluent generation module such that the substantially analyte-free effluent discharged from the analyte concentrator column passes fluidly into the eluent generation module. Eluent generated from the substantially analyte-free effluent in the eluent generation module is likewise substantially free of the analyte. The systems and methods can minimize and/or (substantially) eliminate background signal during analysis of the concentrated analyte.

Systems and methods for concentrating an analyte preparatory to analysis thereof include processing the effluent of an analyte concentrator to produce an eluent for eluting an analyte retained in the same or separate concentrator, and systems implementing the same. The analyte concentrator system connects the effluent outlet of an analyte concentrator column to an eluent generation module such that the substantially analyte-free effluent discharged from the analyte concentrator column passes fluidly into the eluent generation module. Eluent generated from the substantially analyte-free effluent in the eluent generation module is likewise substantially free of the analyte. The systems and methods can minimize and/or (substantially) eliminate background signal during analysis of the concentrated analyte.

A chromatographic cassette includes a cassette including a chamber, chromatographic media disposed within the cassette chamber, a distribution network fluidly coupled to the chromatographic media and an inlet port and an outlet port coupled to the distribution network. A hyper-productive chromatography technique includes providing a scalable and stackable chromatographic cassette, loading a sample to be processed, operating the scalable chromatographic cassette having an adsorptive chromatographic bed having a volume greater than 0.5 liter by establishing a flow at a linear velocity greater than 500 cm/hr with a residence time of the loading step of less than one minute.

An ion chromatography (IC) suppressor includes a first clamping plate, an intermediate plate, a second clamping plate, a first ion exchange membrane, a second ion exchange membrane, a first electrode and a second electrode. The first clamping plate, the intermediate plate and the second clamping plate are tightly buckled in sequence to compact the first ion exchange membrane between the first clamping plate and the intermediate plate and compact the second ion exchange membrane between the intermediate plate and the second clamping plate. Resin particles are filled between the two ion exchange membranes. An eluent inlet and an eluent outlet are provided respectively at two ends of the intermediate plate, and an accommodating groove is formed at each of a tail end of the eluent inlet and a head end of the eluent outlet. The first clamping plate and the second clamping plate are provided with a sealing lip, respectively.

An ion chromatography (IC) suppressor includes a first clamping plate, an intermediate plate, a second clamping plate, a first ion exchange membrane, a second ion exchange membrane, a first electrode and a second electrode. The first clamping plate, the intermediate plate and the second clamping plate are tightly buckled in sequence to compact the first ion exchange membrane between the first clamping plate and the intermediate plate and compact the second ion exchange membrane between the intermediate plate and the second clamping plate. Resin particles are filled between the two ion exchange membranes. An eluent inlet and an eluent outlet are provided respectively at two ends of the intermediate plate, and an accommodating groove is formed at each of a tail end of the eluent inlet and a head end of the eluent outlet. The first clamping plate and the second clamping plate are provided with a sealing lip, respectively.

A method for reacting a reaction object with a liquid containing the reaction object in contact with a granular porous body. The upper limit D (mm) of the particle diameter of the granular porous body is determined from D=0.556×LN (T)+0.166 in a column flow method in non-circulation type, and determined from D=0.0315×T+0.470 in the column flow method in a circulation type and a shaking method. The granular porous body includes a skeleton body including an inorganic compound having a three-dimensional continuous network structure, and has a two-step hierarchical porous structure including through-holes formed in voids in the skeleton body, and pores extending from a surface to an inside of the skeleton body and dispersed on the surface. A functional group having affinity with the metal ion is chemically modified on a surface of the granular porous body.

A method for reacting a reaction object with a liquid containing the reaction object in contact with a granular porous body. The upper limit D (mm) of the particle diameter of the granular porous body is determined from D=0.556×LN (T)+0.166 in a column flow method in non-circulation type, and determined from D=0.0315×T+0.470 in the column flow method in a circulation type and a shaking method. The granular porous body includes a skeleton body including an inorganic compound having a three-dimensional continuous network structure, and has a two-step hierarchical porous structure including through-holes formed in voids in the skeleton body, and pores extending from a surface to an inside of the skeleton body and dispersed on the surface. A functional group having affinity with the metal ion is chemically modified on a surface of the granular porous body.

Described herein is method for testing an ion exchange chromatography device. The method includes monitoring both a binding and a non-binding species and determining their breakthrough point to determine a net breakthrough value. The method can be used to determine the integrity of the chromatography device, ensure that the chromatography device possesses the expected adsorbent capacity, and/or determine viral clearance of the chromatography device.