Use of the zonal centrifuge to separate particles containing transplantation antigen

Subcellular particles of homogenates of mouse spleen were separated at various centrifugal forces between 5000·106 and 30 000·106ω2t in the zonal centrifuge. Each fraction was analyzed for transplantation antigen, ATPase, nonspecific esterase and alkaline phosphatase. Under appropriate conditions, zonal centrifugation proved to be an efficient procedure to seperate particles containing high concentrations of transplantation antigen. After a centrifugal force of 5000·106ω2t, the antigenic particles were located in the 10–12% sucrose region, but they sedimented into denser sucrose particles anecame more disperse when subjected to larger total centrifugal forces. The density of teh particels in CsCl was about 1.2g/cm3. Transplantation antigen was solubilized by autolysis; the antigen was eluted with exclusion volume during gel filtration on Sephadex G-200.