Crossed Immunoelectrophoresis of Membrane Proteins from Acholeplasma laidlawii and Spiroplasma citri

Abstract
Cell membranes from the two mycoplasmas Acholeplasma laidlawii and Spiroplasma citri differ greatly in solubility properties and were, therefore, used as models in this investigation. The membranes were isolated and solubilized with different neutral and anionic detergents. The solutions were analyzed by crossed immunoelectrophoresis in the presence of the corresponding detergent. In the case of A. laidlawii membranes, good results were obtained with the anionic detergent sodium deoxycholate (DOC) and with the neutral detergents Triton X-100 and Tween 20. However, in the case of S. citri membranes, reliable results were obtained only with DOC. These findings indicate that it is preferable to use DOC as solubilizing agent in a standardized procedure of analyzing membrane antigens from different mycoplasmas by crossed immunoelectrophoresis. In experiments with membrane antigens from one mycoplasma and membrane antiserum from another mycoplasma, in order to save time and antisera it is recommended first to run a double diffusion and, if the result is positive, the sample can be further analyzed by crossed immunoelectrophoresis.