During DNA replication, repetitive synthesis of discrete Okazaki fragments 
requires mechanisms that guarantee DNA polymerase, clamp, and primase proteins 
are present for every cycle. In Escherichia coli, this process proceeds through 
transfer of the lagging-strand polymerase from the β sliding clamp left at a 
completed Okazaki fragment to a clamp assembled on a new RNA primer. These 
lagging-strand clamps are thought to be bound by the replisome from solution and 
loaded a new for every fragment. Here, we discuss a surprising, alternative 
lagging-strand synthesis mechanism: efficient replication in the absence of any 
clamps other than those assembled with the replisome. Using single-molecule 
experiments, we show that replication complexes pre-assembled on DNA support 
synthesis of multiple Okazaki fragments in the absence of excess β clamps. The 
processivity of these replisomes, but not the number of synthesized Okazaki 
fragments, is dependent on the frequency of RNA-primer synthesis. These results 
broaden our understanding of lagging-strand synthesis and emphasize the 
stability of the replisome to continue synthesis without new clamps.