Abstract: A process for purifying a lipid composition having predominantly neutral lipid components having at least one long chain polyunsaturated fatty acid is disclosed. The process employs contacting the lipid composition with a polar solvent, such as acetone, wherein the solvent is selected such that contaminants are less soluble in the solvent than is the long chain polyunsaturated fatty acid. The process is typically conducted at cooler temperatures, including about 0° C. Upon precipitation of the contaminants from the lipid composition, a separation is conducted to remove the precipitated material from the lipid composition. The long chain polyunsaturated fatty acids can include ARA, DPA, EPA, and/or DHA. The process of the present invention effectively winterizes lipid compositions, thereby reducing the tendency of such compositions to become hazy.

Abstract: The present invention relates to a process for obtaining lipid from a composition comprising cells and water, said process comprising contacting the composition with a desiccant, and recovering the lipid from the cells. The invention also relates to a lipid obtainable by this process. The process according to then invention enables lipid of high quality to be obtained with a high yield, and does not require a heating step.

Abstract: In a method for quantitating an analyte by measuring time resolved transfer of fluorescence energy to or from a label quantitatively associated with the analyte, the present invention provides an improvement comprising measuring the energy transferred from donor compounds having the ability to absorb light energy and then transfer this energy to cross-linked allophycocyanin in a time-resolved manner, where the cross-linked allophycocyanin used according to this invention has not been exposed to strongly chaotropic agents after cross-linking.

Abstract: This invention is concerned with determining the three-dimensional structure of biological macromolecules such as proteins. In particular, it is concerned with methods for rapidly determining protein structure by NMR, by providing methods for simplifying NMR spectra using labeled proteins prepared from specifically isotopically labeled amino acids having at least two isotopes of 13C, 15N and 2H in the backbone, and methods for making these labeled proteins, e.g., by cultivation of a microbial culture containing said labeled amino acids.

Abstract: A method for determining three-dimensional structural information of a protein involves producing the protein in a form substantially labeled with .sup.13 C or .sup.15 N or both and subjecting the protein to nuclear magnetic resonance spectroscopic analysis. The isotopically labeled protein is produced by a method which involves producing a substantially labeled microbial protein hydrolysate, subjecting the protein hydrolyzate to cation exchange chromatography to produce a partially purified labeled amino acid mixture, subjecting the partially purified labeled amino acid mixture to anion exchange chromatography to produce a purified labeled amino acid mixture and supplementing the purified labeled amino acid mixture with isotopically labeled cysteine.