This study was carried out to identify the interacting partners of Leishmania donovani Cdc45, a protein that is conserved in eukaryotic DNA replication. Accordingly, Cdc45 was expressed in Leishmania promastigotes with a C terminal FLAG tag and whole cell lysates were isolated from these Ld1S transfectant promastigotes. Whole cell lysates were also isolated from promastigotes harbouring empty vector. These lysates were used in immunoprecipitation reactions with anti-FLAG antibodies.