SMC1L1/SMC1 (structural maintenance of chromosome 1-like 1 (yeast)) is a 145-160 kD heterodimeric protein that is a member of the SMC family. This nuclear protein dissociates from chromosomes before mitosis but remains associated with kinetochore during mitosis. SMC1L1/SMC1 is located on the X-chromosome and is involved in mitotic chromosome dynamics. The SMC family includes SMC3, SMC1L1, and SMC1L2 which form part of the cohesion multiprotein complex. This protein can also form heterodimers consisting of SMC1L1/SMC3 or SMCL2/SMC3 and may also be involved in DNA repair. SMC1L1/SMC1 is phosphorylated by ATM after DNA damage; phosphorylation is also required for sister chromatid cohesion and correct segregation of chromosomes during cell division. SMC1L1/SMC1 associates with BRCA1, and SYCP2, and interacts directly with SMC3 in the cohesion complex (linked by RAD21 complexed to one STAG protein). The Poly6096 antibody recognizes the N-terminal region of human and mouse SMC1L1/SMC1 and has been shown to be useful for Western blotting and immunofluorescence staining.