RT-PCR analysis of the AML1-MTG16 and theMTG16-AML1 chimeric transcripts in four t(16;21) patients. Poly(A)⁺ RNA and total RNA samples from peripheral blood were reverse transcribed into cDNA. The primer pairs, AML1ex5f1 and MTG16r2, MF1 and AML1ex6r2, AML1ex4f2 and AML1ex6r2, and MF1 and MTG16r2 were used for amplification of AML1-MTG16 (A),MTG16-AML1 (B), AML1 (C), and MTG16 (D) transcripts, respectively (their locations are shown in Fig 6). Lane 1, poly(A)⁺ RNA from patient no. 1; lanes 2 through 5, total RNA from patients no. 1 through 4; lanes 6 and 7, total RNA from normal individuals; lane 8, template-free. Arrows indicate the detected transcripts with their sizes in bp. The two AML1-MTG16 chimeric products (545 bp in lanes 1 through 4 and 773 bp in lane 5 seen in [A]) and the one MTG16-AML1 chimeric product (357 bp in lanes 1 and 2 seen in [B]) were purified and sequenced.