[Purification of skin reactive factor (SRF) in mice]

For the purification and further characterisation of the skin-reactive factor (SRF) of the mouse, the SRF-containing ascitic fluid of Ehrlich ascites tumor was exposed to different separation or elution procedures. After preliminary purification by (NH4)2SO4 precipitation when the total activity was not in the dialysable supernatant, gel-chromatographic separation (Sephadex G-200), immune electrophoretic investigations as well as ion exchange chromatography were performed. The skin-reactive activity in fraction I of gel chromatiography is presumably caused by a toxic substance with skin-irritating properties. The SRF demonstrable in fraction II/2 has a molecular weight similar to that of albumin, can be found in the ion exchange chromatography (DEAE-Sephadex A-50-column) in fraction III, and is of proteinic nature.