[Differentiation of Brucella by acrylamide-gel electrophoresis (author's transl)]

The strains of Brucella (Tab. 1) were grown on Tryptose-blood-agar at 37 degrees C, and the strains of Bordetella, Pasteurella and Actinobacillus on blood-agar. After 24 or 48 h they were harvested and extracted in phenol-acetic acid-water solution (4:2:1) (1 ml/50 mg bacterial wet weight) at 4 degrees C over 48 h. After centrifugation (8000 X g, 1 h) 2 volumes of the supernatant were mixed with 1 volume of a 40% sucrose solution in 35% acetic acid. Different volumes (0.20, 0.15 or 0.10 ml) of this were added to 7.5% acrylamide gel (2 ml in tubes 6 X 100 mm), containing 5 M urea and 12% acetic acid. The solution in both electrode chambers was 10% acetic acid. During the first 15 min it was focused with 2 mA/tube, then it was separated for 3 or 5 h with 4 mA/tube. The protein bands were stained with amido black 10B. All species could be exactly differentiated from each other, but the protein bands of biotypes of Bruc. suis, Bruc. melitensis and Bruc. abortus were identical in each case. All investigated strains of Bruc. canis were identical too. A small relationship was noticed between Bruc. canis and Bruc. suis and between Bordetella bronchiseptica and Bruc. canis respectively Bruc. suis strains.