Buffer generators are described based on electrodialytic devices. The methods of using these devices can generate buffers for diverse applications, including separations, e.g., HPLC and ion chromatography. Also provided are chromatographic devices including the buffer generators, generally located upstream from a chromatography column, sample injector valve or both.

The present invention relates to a novel method for purifying teriparatide, a therapeutically active polypeptide fragment of full-length human parathyroid hormone. The method is based on ion exchange chromatography and is effective in separating the therapeutically active polypeptide from undesirable variants, such as truncated polypeptides. The method of the invention can be used at a preparative scale which allows it to be implemented into the production process for teriparatide. Accordingly, the invention also provides a method for the production of teriparatide which includes a step in which teriparatide is purified by the novel ion exchange chromatography method of the invention.

Improved mobile phase buffer compositions, methods, and kits are provided for pH gradient LC-MS characterization of monoclonal antibodies and charge variants thereof.

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 are provided for enhancing reduction of virus and viral DNA levels in protein preparations.

The present invention relates to a method of separating single-stranded RNA (ssRNA) molecules from other nucleic acid species and to the use of a solid phase for separating ssRNA molecules from other nucleic acid species. The invention claims that ssRNA could be eluted from a solid phase media comprising multimodal ligands comprising nitrogen-containing heterocycles in an ascending pH gradient with: 1) a high product recovery at room temperature, 2) in the proximity of neutral pH, 3) without harmful additives.

An electrodialytic buffer generator is described. The buffer generator may include a central buffer-generating channel having an inlet and outlet, a second chamber, and a third chamber. The buffer-generating channel, the second chamber, and the third chamber may each include an electrode. The buffer generator may also include a first ion exchange barrier and a second ion exchange barrier. The first ion exchange barrier can be disposed between the second chamber and the buffer-generating channel. The second ion exchange barrier can be disposed between the third chamber and the buffer-generating channel.

The present invention relates to a novel method for purifying teriparatide, a therapeutically active polypeptide fragment of full-length human parathyroid hormone. The method is based on ion exchange chromatography and is effective in separating the therapeutically active polypeptide from undesirable variants, such as truncated polypeptides. The method of the invention can be used at a preparative scale which allows it to be implemented into the production process for teriparatide. Accordingly, the invention also provides a method for the production of teriparatide which includes a step in which teriparatide is purified by the novel ion exchange chromatography method of the invention.

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 salts, and one or more solvents, and the method comprises the steps of: i) calculating pH and/or salt concentration at a particular time t from a user-determined gradient function; and ii) based on the values obtained in step (i), calculating percent acid, percent base, percent salt and percent solvent in the liquid mixture at time t. A liquid chromatography system incorporating such method is also provided.

An electrodialytic buffer generator is described. The buffer generator may include a central buffer-generating channel having an inlet and outlet, a second chamber, and a third chamber. The buffer-generating channel, the second chamber, and the third chamber may each include an electrode. The buffer generator may also include a first ion exchange barrier and a second ion exchange barrier. The first ion exchange barrier can be disposed between the second chamber and the buffer-generating channel. The second ion exchange barrier can be disposed between the third chamber and the buffer-generating channel.