Figure 2.
Measured ejection fractions as a function of added salt concentration, against an osmotic pressure (3.5 atm) induced by PEG8000 solution. Note that the zero of the abscissa corresponds to 10 mM Mg2+ already present in the buffer solution. (a) Added MgSO4. (b) Added MgCl2. (c) Added SpCl4. In panel a we show two sets of data, for two different phage batches (open circles and squares, with associated error bars estimating the experimental uncertainties); results from a calculation of repulsion and bending energies (×); and estimates from neglect of bending energy, using measured d-spacings (+). The data in panels a and b refer to wild-type λ-samples, whereas panel c involves a shorter-genome-length (94%) mutant.