A few months ago we made some mouse monoclonal antibodies to the interesting cell division and cancer related Aurora A, a highly conserved serine/threonine protein kinase. These seemed to work very well but we subsequently found that some of them cross-reacted with the very closely related Aurora B. We therefore went to the trouble of expressing all three members of the human Aurora kinase family, Aurora A, B and C, and we now have mouse monoclonals which are monospecific for each individual Aurora family member (Aurora A = MCA-1A11, MCA-1A14, Aurora B = MCA-3F11, MCA-6G2, Aurora C = in progress, will update on that shortly). We also have a pan-specific mouse monoclonal antibody which will bind all three Aurora proteins (MCA-4A7) and two monoclonals which bind Aurora A and B but not C (MCA-5A12, MCA-3H1). All members of this panel of novel antibodies work very well on western blots of crude extracts of HeLa cells and in immunocytochemistry on cells in tissue culture. They should therefore be useful as markers of midbodies, spindles and polar bodies in dividing cells and for developmental and cancer related studies.