EMSA using oligonucleotide probes with RUNX1-binding sites 1A, 1B, 2, and 3 and recombinant RUNX1. (A) EMSA using oligonucleotide probe with sites 1A and 1B and recombinant RUNX1. Lane 1 indicates probe alone; lane 2, probe with recombinant RUNX1; lane 3, competition with excess unlabeled probe; lane 4, effect of RUNX1 antibody (arrow, supershift); and lane 5, effect of nonspecific IgG. (B) EMSA using recombinant RUNX1 and oligonucleotide probes with site 2 (−708/−703; lanes 1-5) and with site 3 (−526/−521; lanes 6-10). Lane 1 indicates free probe with site 2; lane 2, protein binding with recombinant RUNX1; lane 3, competition with excess unlabeled probe; lane 4, effect of RUNX1 antibody (, supershift); lane 5, effect of nonspecific IgG; lane 6, free probe with site 3; lane 7, protein binding with recombinant RUNX1; lanes 8, competition with excess unlabeled probe; lane 9, effect of RUNX1 antibody (, supershift): and lane 10, effect of nonspecific IgG.