Table 2 Calculated surface charge densities and planes of shear of the S. Minnesota LPS. The areas per molecule A were calculated according to Snyder et al [29], using the respective amounts of fatty acids determined from mass spectrometric data. The charge densities σ were calculated from A and the net negative charges given in Tab. 1. d1 and d2 represent the distances of the planes of shear from the aggregate surface taking into account 1 or 2 charged planes, respectively.