The Effect of Dissociation on the Electrophoretic Mobility of Brucella

Abstract

Electrophoretic measurements under carefully controlled conditions on strains of B. abortus dissociated in broth indicate that dissociation may be a gradual process. Dissociated forms (mucoid) haying a greater mobility than the S appear after a few days in broth without the complete disappearance of organisms having the mobility values of S forms. Dissociated forms having appreciably different mobility values may be separated by colony appearance when a given technique is used. Passage of dissociated forms of Brucella of high mobility through guinea pigs causes a decrease in mobility value to that of the S forms without loss of mucoid character. Serol. tests show that M organisms of low mobility are similar antigenically to M forms of high mobility, but are appreciably different from the original S organisms. The complexity of the subject of dissociation is emphasized and lines of further investigation are indicated.