The Okazakis discovered what became known as Okazaki fragments, short sequences of DNA nucleotides (approximately 150 to 200 base pairs long in eukaryotes) which are synthesized discontinuously and later linked together by the enzyme DNA to create the lagging strand during DNA replication. Before this discovery it was commonly thought that replication was a continuous process for both strands, but the discoveries involving E. coli led to a new model of replication. The Ozakis found that there was a discontinuous replication process by pulse-labeling DNA and observing changes that pointed to non-contiguous replication.

The Ozakis published their results in 4 papers:

2. "Mechanism of DNA Chain Growth, II. Accumulation of Newly Synthesized Short Chains in E. coli Infected with Ligase-Defective T4 Phages," Proc. Nat. Acad. Sci. (USA) 60, (1968) 1356-1362.
3. "Mechanism of DNA Chain Growth, III. Equal Annealing of T4 Nascent Short DNA Chains with the Separated Complementary Strands of the Phage DNA," Proc. Nat. Acad. Sci. (USA), 63 (1969) 1343-1350.
4. "Mechanism of DNA Chain Growth, IV. Direction of Synthesis of T4 Short DNA Chains as Revealed by Exonucleolytic Degradation," Proc. Nat. Acad. Sci. (USA) 64 (1969) 1242-1248.
Digital facsimiles of all 4 papers are available from PubMedCentral.