The present invention relates to methods for purifying nucleic acids. In particular, the present invention relates to a method for separating guanine-rich oligonucleotides from quadruplex secondary structures formed from the oligonucleotides using monolithic anion exchange chromatography. Mobile phase parameters that control quadruplex formation and enable separation of the intact quadruplex from the single-strand oligonucleotide are also described.

The present disclosure generally relates to methods for separating Δ.sup.8-THC, Δ.sup.9-THC, and related enantiomers using CO.sub.2-based chromatography.

The invention provides methods and formulations comprising a protein comprising solvent accessible amino acid residues susceptible to oxidation wherein N-acetyl tryptophan (NAT) is used to prevent oxidation of the protein. The invention also provides methods for making such formulations and methods of using such formulations. Methods to measure degradation of NAT in protein formulations are also provided.

The invention discloses a method for predicting the pH error during mixing of an aqueous buffer comprising at least one weak acid species and/or at least one weak base species, which comprises the steps of: a) selecting a start composition of the buffer, giving start values for pH and/or buffer concentration; b) calculating the concentrations of all ionic species present in the buffer at a specified pH value from the total composition of the buffer and available dissociation constants; c) calculating the contribution of each of said ionic species to a total pH variance from the specified pH value, the buffer concentration, the calculated concentrations of the ionic species and variances in amounts of buffer components; d) calculating the pH variance, and; e) setting the variance or the square root of the pH variance as the pH error.

A method for producing lead-212 of very high radiological purity from an aqueous solution comprising thorium-228 and daughters thereof. Manufacture of radiopharmaceuticals based on lead-212, which are useful in nuclear medicine and, in particular, in targeted alpha radiation therapy for the treatment of cancers.

The disclosure relates to a gradient twin column recycling chromatography method that is used to separate a mixture containing closely eluting compounds. In one embodiment, a sample includes a primary organic compound and one or more impurities that closely elute with the primary organic compound. A gradient mobile phase is initially used to remove unwanted early eluting and late eluting impurities from the sample. After the gradient removal of some of the impurities is complete, the remaining mixture of the primary organic compound and the closely eluting impurities are separated using recycle chromatography methodology with an isocratic mobile phase.

An arrangement (2; 32) for adding a first fluid component into a flow system (1; 31), said arrangement comprising: a first pump (3; 33) provided in a first component adding fluid line (5; 35) which is connecting a first system fluid line (9; 39) of the flow system (1; 31) with a first fluid component source (7; 37) comprising the first fluid component to be added into the flow system; and a second pump (13; 43) provided in a second component adding fluid line (15; 45) connected in parallel with the first component adding fluid line (5; 35), said second component adding fluid line (15; 45) connecting the first system fluid line (9; 39) of the flow system with a first fluid component source (7; 47) comprising the first fluid component to be added into the flow system.

Provided herein are methods of separating host cell lipases from a production protein in chromatographic processes and methods of improving polysorbate-80 stability in a production protein formulation by separating host cell lipases from the production protein using chromatographic processes. Also provided are pharmaceutical compositions comprising less than 1 ppm of a host cell lipase.

Materials and methods for use of constrained cohydration agents in the purification of biological materials such as antibodies, viruses, cells, and cellular organelles in connection with convective chromatography, fluidized bed or co-precipitation applications.

The present invention relates to a column chromatographic method of manufacturing non-carrier-added high-purity .sup.177Lu compounds for medicinal purposes. In the method in accordance with the invention a cation exchanger and a suitable chelating agent are used. With the method in accordance with the invention it is possible for the first time to provide non-carrier-added high-purity .sup.177Lu compounds in milligram amounts for pharmaceutical-medicinal purposes from .sup.176Yb compounds irradiated with thermal neutrons, the radionuclides .sup.177Lu and .sup.176Yb being present in an approximate mass ratio of 1:10.sup.2 to 1:10.sup.10 for purification.