[Characterization of the membrane attached to the folded chromosome isolated from Escherichia coli]

Phospholipid analysis of the membranes associated with fast sedimenting folded chromosomes prepared by lysis of E. coli CR 34 shows that both inner and outer membranes are parts of the complex, in proportions not very different from that found in the whole bacteria. During the preparation of the folded chromosomes, the most recently synthesized molecules of phosphatidylglycerol and phosphatidylethanoamine are more sensitive to solubilisation, particularly those from the cytoplasmic membrane. Identification of a dominant fraction, the outer membrane, in some complexes, results from a preferential solubilization of the inner membrane. These results do not favor any specific association between the folded chromosome and the membranes.