Dissecting the Cell-Killing Mechanisms of Hydroxyurea Using Spot Assays

Hydroxyurea is an inhibitor of ribonucleotide reductase and is commonly used in laboratories to induce replication stress or arrest cells in the S phase for cell cycle or checkpoint studies. However, hydroxyurea also causes side effects such as oxidative stress, particularly under chronic exposure conditions. This complicates the interpretation of the cell-killing mechanisms, particularly in a previously uncharacterized mutant, and thus hampers the analyses. Here, we describe a few easy and simple spot assays in fission yeast that allow dissecting the cell-killing mechanisms of hydroxyurea.