Abstract: Membrane proteins are isolated from Neisseria meningitidis by direct treatment of the cells with a detergent. The membrane proteins can be worked up into a vaccine.

Abstract: For improving the stability of menningococcal polysaccharides in aqueous solution, lactose is completely or partially replaced by another compound which forms a hydrate and can be reversibly dehydrated under the conditions of lyophilization. The mixture may then be dried and/or processed to a vaccine.

Abstract: What is disclosed is a method for the isolation of the polyvalent proteinase inhibitor from aqueous extracts of animal organs by adsorbing the inhibitor from its aqueous solutions at pH 0.5 to 10.5 on an ion exchanger containing functional sulfonate or phosphonate groups and eluting it with water or a salt solution at pH 1 to pH 13, the exchanger having a particle size from 0.03 to 0.08 mm or, in case the ion exchanger is a copolymer gel of ethene-sulfonate and acrylamide, having a particle size from 0.03 to 3 mm preferably from 0.06 to 0.3 mm.