Relationship between the acceptor/donor radioactivity ratio and cross-linking in bacterial peptidoglycan: application to surface synthesis during the division cycle.

The relationship between the experimental measurement of the cross-linking of bacterial peptidoglycan and the mode of its insertion is analyzed. The cross-linking value, in practice and in theory, is independent of the pattern of strand insertion. Since the measure of the mode or pattern of insertion is the acceptor/donor radioactivity ratio (ADRR), no correction need be made for the ADRR. The measurement of cross-linking using radioactivity is independent of the labeling time, the specific activity of the label, and the mode of strand insertion. It is not concluded, however, that cross-linking does increase during the division cycle.