Abstract: A method of analysing gene expression occurring in a microorganism before, during or after contact with or adhesion of the microorganism to a lipid bilayer, comprising the step of exposing the microorganism to a lipid bilayer, wherein the lipid bilayer is substantially not associated with protein or RNA synthetic machinery. The lipid bilayer may be a red blood cell membrane, for example in the form of intact red blood cells. The red blood cells may be immobilised as a monolayer. The microorganism may be an enteropathogenic or enterohaemorrhagic E. coli. A DNA or protein microarray may be used in analysing gene expression.