A method of preparing a liquid mixture for use in a liquid chromatography system is provided. The mixture comprises one or more acids, one or more bases, one or more solvents and water, and the method comprises the steps of: calculating pH and/or solvent concentration at a particular time t from a user-determined gradient function; and, based on the values obtained, calculating percent acid, percent base, percent solvent and percent water in the liquid mixture at time t. A liquid chromatography system incorporating such method is also provided.

Herein is reported the use of an immobilized non-covalent complex of a neonatal Fc receptor (FcRn) and beta-2-microglobulin (b2m) as affinity chromatography ligand in general and, for example, for the determination of the in vivo half-live of an antibody by determining the ratio of the retention times of the antibody and a reference antibody.

In an LC system using an ODS column (15) and UV detector (17), a cannabis-derived sample is analyzed by gradient elution using a phosphoric acid aqueous solution and phosphoric-acid-containing methanol. A control unit (3) regulates the openings of solenoid valves in a mixer (12) so that the increase rate of the mixture ratio of the phosphoric-acid-containing methanol in a second part of the analysis period is higher than in a first part. By this operation, ten active ingredients (including Total THC, Total CBD and CBN) contained in cannabis can be satisfactorily separated within an analysis time which is equal to or even shorter than approximately 30 minutes. Each ingredient separated by the column (15) is detected by the UV detector (17). An active ingredient identification processor (22) identifies the ten active ingredients based on the retention times of the peaks on a chromatogram created from the detection signals.

Herein is reported a method for determining the presence of antibody-Fab-FcRn interaction in an antibody-Fc-FcRn complex influencing the in vivo half-life comprising the steps of a) determining the retention time of the antibody on an FcRn affinity chromatography column with a positive linear pH gradient elution in the presence of a first sodium chloride concentration, and b) determining the retention time of the antibody on an FcRn affinity chromatography column with a positive linear pH gradient elution in the presence of a second sodium chloride concentration, whereby the presence of antibody-Fab-FcRn interaction in an antibody-Fc-FcRn complex influencing the in vivo half-life is determined if the retention time determined in step a) and the retention time determined in step b) are substantially different.

The invention relates to the field of protein purification processes involving several chromatography steps. The invention pertains to a method for purifying a protein, preferably an antibody or fragment thereof or a protein containing said fragment, from a complex solution, wherein said method comprises at least two chromatography steps which are performed using buffers comprising or consisting of the same chemical compounds. The invention is particularly useful for large scale production and purification of recombinant proteins.

Methods for purifying multispecific antibodies on interest (MAIs) that co-engage at least two different antigens or epitopes (also referred to targets, used interchangeably throughout), from compositions comprising the MAI and parental homodimeric antibody species are provided, as well as reagents which may be used to practice such methods.

Methods for purifying multispecific antibodies on interest (MAIs) that co-engage at least two different antigens or epitopes (also referred to targets, used interchangeably throughout), from compositions comprising the MAI and parental homodimeric antibody species are provided, as well as reagents which may be used to practice such methods.

A method for preparing an aqueous solution of a defined pH comprising an acid, a base and optionally one or more additives is provided. The method comprises the steps of:

a) calculating the theoretical concentrations of acid and base for the solution to have the defined pH using the Henderson-Hasselbach equation in combination with the Debye Huckel theory for a range of different additive concentrations; b) preparing a sample of the buffer for the range of additive concentrations and measuring the actual pH for each additive concentration; c) calculating a value for delta pH, pH, being the difference between the theoretical pH and the actual pH, for each additive concentration; d) generating a mathematical model describing the relationship of pH with additive concentration; e) selecting the defined pH and additive concentrations; f) using the mathematical model generated in step d) to calculate pH for the defined pH and additive concentration; g) calculating a pH-corrected pH by summing the defined pH and delta pH; h) using the pH-corrected pH to calculate the concentrations of acid and base using the Henderson-Hasselbach equation in combination with the Debye Huckel theory; i) preparing the solution using the concentrations calculated in step h).

A device and method for the separation of a compound or compounds from impurities is described. The device comprises a tube having a mixing apparatus that mixes by convection a feedstock comprising one or more products such that the products can be bound to a resin and then contacted with various buffer solutions. At various distances along the cylindrical module, solutions (e.g., sample products to be purified, buffers, etc.) of various compositions can be sequentially added and removed. The resin particles can be retained within the module by filters or screens at the addition and exit ports. In this way, a slurry of resin particles can be continuously equilibrated, loaded with product, washed of impurities, eluted of processed product(s), stripped, re-equilibrated and recycled for re-use.

A method of preparing a liquid mixture for use in a liquid chromatography system is provided. The mixture comprises one or more acids, one or more bases, one or more solvents and water, and the method comprises the steps of: calculating pH and/or solvent concentration at a particular time t from a user-determined gradient function; and, based on the values obtained, calculating percent acid, percent base, percent solvent and percent water in the liquid mixture at time t. A liquid chromatography system incorporating such method is also provided.