Gel mobility shift/supershift assay of MEL cell extracts. Five-microgram aliquots of nuclear extracts from untreated (lanes 1, 3, 4, 5, 6) or DMSO-treated (lane 2) 745A cells were incubated with end-labeled oligomers corresponding to the GATA site (−59/−54) in the absence (lanes 1 and 2) or presence of a 250-fold molar excess of the indicated oligonucleotides (lanes 3, 4, 5) or anti–GATA-1 antibody (lane 6). The arrowhead indicates the complex of the probe and GATA-1, and the arrow represents the ternary complex of the probe, GATA-1, and the antibody.