We propose an innovative approach combining two separate, novel techniques to greatly enhance accurate detection of leukemia or lymphoma cells, which can be used ultimately for diagnostics and early detection of minimal residual disease (MRD) in bone marrow, lymph nodes, and peripheral blood. The novel techniques of our approach are: (1) A two-step method to generate repetitive sequences depleted DMA probes. The method includes subtracting hybridized biotin-labeled repetitive-sequence DNA complex with phenol and chloroform and a second subtraction using avidin labeled magnetic beads. The unique sequences are then recovered using our dual unique sequence primers. (2) A novel technique of hybridizing chromosomes in suspension with fluorescently-labeled repetitive sequences depleted DNA probes, in combination with flow cytometric analysis or magnetic sorting, in order to sensitively, precisely and rapidly quantify leukemia or lymphoma-related chromosome translocations and rearrangements. Morphologic examination has a detection sensitivity of 1 in 100. PCR technique is very sensitive, but lack of accurate quantitation still is a problem. By contrast, hybridizing chromosomes in suspension has a potential sensitivity of 1 in 1,000,000. We propose to use leukemia as a model to demonstrate solution hybridization technique in conjunction with repetitive sequences depleted DNA probes as a sensitive and specific technique for accurate detection of MRD. Early detection of MRD will increase patient survival and profoundly impact cancer patient management
