METHOD OF REDUCING CONTENT OF ENDOTOXIN IN SAMPLE CONTAINING POLYSIALIC ACID AND ENDOTOXIN Russian patent published in 2013 - IPC C08B37/00 C12N1/00 C12P1/04 

FIELD: chemistry.

SUBSTANCE: invention relates to biochemistry. A base having pKa 12-13 is added to a sample and incubated for 5 minutes to 24 hours at temperature of 0-60°C. The sample is passed through an anion-exchange column, wherein polysialic acid (PSA) is adsorbed on an anion-exchange resin. The column is washed with a buffer having low ionic force, which contains NaCl in concentration of 0.2M. The polysialic acid is eluted from the column using a buffer having higher ionic force. The step for washing the column is repeated multiple times. The method may additionally include preliminary steps: neutralisation, incubation of the sample with a surfactant, a chelating agent, an organic solvent, an oxidant or peroxidase, a step for cleaning using ion-exchange, affinity, size-exclusion chromatography, using hydrophobic-interaction chromatography or combinations thereof. A sample is obtained, having low endotoxin content, wherein PSA is poly(2,8-combined sialic acid), poly(2,9-combined sialic acid), alternating 2,8-2,9-combined polysialic acid, colominic acid or an oxidised, reduced, aminated and/or hydrazide derivative thereof. To obtain a sample of culture broth containing polysialic acid and endotoxin, Escherichia coli is pre-cultured, wherein the method may include intermediate steps for removing protein, lipids, nucleic acids and/or nutrients.

EFFECT: low content of endotoxin in the sample of not more than 1407 EU/mg PSA or not more than 300 EU/mg PSA.

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