Method for obtaining a C cell polysaccharide antigen containing no more than 10% of the Streptococcus pneumoniae bacterium protein, which comprises the following steps: a) culture of the bacterium for the necessary time, to obtain a sample of the desired dimensions, and collect the bacterial cells thereof in the form of a wet tablet of the cells; b) suspend the wet tablet from the cells in an alkaline solution and mix; c) adjust the pH to an acidic pH value, with a strong acid and centrifuge; d) separate the supernatant from step (c) and adjust its pH to an approximately neutral value; e) digest this product with a broad-spectrum protease enzyme preparation to destroy residual proteins; f) separating the carbohydrate or polysaccharide antigen essentially free of protein in a dimensional exclusion column balanced with a weak alkaline solution.
展开▼
