RESUMEN
The paper discusses the problems of purification of Provachek's rickettsias used to prepare typhus vaccines and diagnostic kits. The currently available agents contain many admixtures of rickettsias products, more commonly yolk and chick embryo yolk sack cell detritus, which make it impossible to determine the true antigenic properties of rickettsias in the context of protection and diagnosis. By applying the well-known principle of distribution of biological particles in the two-phase systems of water soluble polymers, investigations were made to examine the distribution of rickettsias and their infected biological mass in the system: polyethylene glycol-6600, sodium-500 dextran sulfate, potassium phosphate, sodium chloride in order to prepare agents of pure rickettsias. It has been found that rickettsias are distributed in the polymer-enriched phase, their number and the degree of purity when isolated from the infected biological mass depends on the capacity of an interphase wherein tissue detritus sorption occurs.