Polo-like kinase 1 (Plk1) is an important protein kinase for checkpoint recovery and adaptation in response to DNA damage and replication stress. However, although Plk1 is present in S phase, little is known about its localization and function during unperturbed DNA replication. Here we used a previously described Chromatin Mass spectrometry (Chromass) protocol (Project PXD000490) to compare the protein recruitment on chromatin in Xenopus egg extracts during unperturbed DNA replication in the presence or after Plk1 depletion from the extract.