Detection sensitivity of 1% tumor cells with t(11; 14)(q13; q32) within peripheral blood by competitive RT-PCR. Peripheral blood (100 μL) of a normal volunteer was mixed as an indicated percentage with mononuclear cells from a patient with chronic lymphocytic leukemia (CLL) with t(11; 14)(q13; q32) and subjected to RNA extraction and the competitive RT-PCR as described in Materials and Methods. Arrows indicate PCR products corresponding to cyclins D1, D2, and D3. Negative control of PCR without added template is in lane 9. The sizes (bp) of 100 bp DNA ladders (lane 1) are shown on the left.