Four different detergents, ASB 14, SB 3-10, CHAPS and Triton X100, were utilized to determine the optimal detergent for the solubilization of membrane proteins from the phytopathogenic bacterium Xylella fastidiosa. These proteins were differentially solubilized in distinct buffers containing the detergent and subjected to bidimensional electrophoresis within the non-linear pH range of 3-10. The detergents ASB 14 and SB 3-10 were the most effective revealing 221 and 157 spots, respectively. CHAPS and Triton X 100 were less effective and revealed only 72 and 43 spots, respectively. MALDI-TOF tryptic peptide mass fingerprinting of 18 excised proteins from the ASB 14 treatment revealed that 83% were membrane proteins and that the theoretical efficiency of solubilization for ASB 14 was estimated to be 87%. This study demonstrates the effectiveness of the detergent ASB 14 for the solubilization of membrane proteins from the bacterium X. fastidiosa.