(A) Second round TEL-AML1 transcript showing positive full term infant cord blood samples. Lane 1, 100 bp ladder; 2, positive cord blood (a); 3, positive cord blood (b); 4, 10-4 REH (TEL-AML1+) cells diluted in SV18 (normal lymphoid) cells; 5, as 4, but REH diluted 10-5 with SV18; 6, water (negative) control; 7, normal lymphoid cell line SV18. (B) Second round BCR-ABL transcript from single preterm infant sample (for details, see text). Lane 1, 100 bp ladder; 2, b2a2/b3a2 (p210) transcript; 3, E1a2 (p190) transcript; 4, ß actin positive control; 5, water (negative) control.