PCR analysis of clonotypic genomic AML1-ETOfusions in neonatal Guthrie cards of leukemic patients.

Two rounds of PCR (70 total cycles) were performed as described in “Patients, materials, and methods,” and the results are shown only from the secondary round. Partial results are shown; in most cases a second PCR run was performed. Five “positive” PCR patients are shown, as well as one negative. Lane markers: M indicates marker. Lanes 1-6 show 1:10 dilutions of patient DNA, with lane 1 being 100 ng/μL and lane 6, 1 pg/μL DNA. Patient DNAs have varying percentages of leukemic DNA, as some patient samples are from blood rather than bone marrow. C indicates control Guthrie card without patient DNA; P, Guthrie card segment from the patient; P, patient Guthrie card segment that was sequenced and determined to be the same sequence as the diagnostic DNA sample of that patient; B, no DNA sample (blank).