Double fluorescence labeling of COS-7 cells transfected with the constructs of full-length or mutant chimeric proteins and PEBP2β. A total of 3 × 10⁴ COS-7 cells were transfected with 4 μg of each construct together with 0.4 μg of the expression plasmid for PEBP2β. (a, b, c, and d) The chimeric proteins were detected with anti-AML1 serum. (e, f, g, and h) PEBP2β was detected with hamster anti-PEBP2β serum. Original magnification × 600.