Electron density profiles of pure Di22:1PC and antibiotics or cholesterol in Di22:1PC at various molar ratios. (A) Penicillin was mixed with Di22:1PC bilayers at molar ratios of 0, 1/50, 1/15, and 1/5. (B) Sulbactam was mixed with Di22:1PC bilayers at molar ratios of 0, 1/50, 1/15, and 1/5. (C) Cholesterol was mixed with Di22:1PC bilayers at molar ratios of 0, 1/50, 1/25, 1/15, 1/10, and 1/5. The profiles were not normalized and were displaced for clarity. The short vertical bars indicate the positions of the peaks.