Sensitizing Activities of the Three Fractions Obtained from Human Strain H2 Tuberculin

A lyophilized material (DRIED Tuberculin or DT) was prepared from an unheated, concentrated filtrate of a eight weeks' culture of human strain H2. It was fractionated into five fractions by means of zone electrophoresis employing starch as the supporting medium. Three of them, one polysaccharide fraction and two protein fractions (Fr.-II and Fr.-III), were tested in comparison with DT for their sensitizing activities on guinea pigs.Each of these fractions or DT with Drakeol: Arlacel mixture was injected intramuscularly into a group of guinea pigs. Thereafter the development of the tuberculin allergy of the animals in terms of skin reactivity was examined periodically, i. e. the 3rd, 6th, and 9th week after sensitization, by an intradermal injection with 5r of PPD, . At the 7th week after the sensitization the degree of the skin reactivities to each preparation of the animals of the four groups was compared by intradermal injections of 1 r each of the polysaccharide fraction, the protein fractions, and DT. The results obtained are as follows:1) Among these preparations DT showed the highest sensitizing activity and Fr.-II followed. The polysaccharide fraction and Fr.-III showed lower activities than the others.2) The difference between the homologous anh heterologous reactions was regarded as an indication on the differences in specificity of these preparations according to the Magnusson's paper. Fr.-II seemed to be more specific than Fr.-III in sensitizing or skin reacting activity.