Characterization of RB1 Deletions in Interphase and Metaphase by Molecular Cytogenetics Exemplified in Chronic Lymphatic Leukemia.

In chronic lymphatic leukemia (CLL), detection and characterization of prognostic relevant chromosomal alterations is optimally done by interphase-fluorescence in situ hybridization (iFISH). Interphase nuclei derived from blood smears, bone marrow smears or from cultivated and conventionally prepared blood or bone marrow cells can be used. In CLL heterozygous or even homozygous deletion of RB1 can be found. Interestingly an iFISH diagnostic result with RB1 deletion as sole aberration is indicative for a favorable course of the disease. Here we describe the best way how to detect RB1 deletion in CLL.