This kit consists of three sets of probes: RB1/ATM, P53/CEP17, and D13S319/CEP12. The probes of RB1, P53 and D13S319 use an orange-red fluorescent label, and ATM, CEP17 and CEP12 probes are labeled with a green fluorescence. The probes are combined with the target sites by in situ hybridization. Under normal conditions (no gene deletion and chromosome abnormalities), two orange-red signals and two green signals are shown under a fluorescence microscope. When there is gene deletion, there will be a lack of green or orange-red signal, and when there is a chromosomal polysomy, the centromere gene probe signal will increase. This method is used to detect gene deletion and chromosome abnormalities, and provide reference for clinical differentiation, prognosis and medication for leukemia patients.