Chromosome Enumeration Probes are designed for identification and enumeration of human chromosomes in interphase cells and as an adjunct to standard karyotyping in metaphases. These probes will produce sharp, bright signals specific for each individual chromosome. 

As several chromosomes share the same repetitive sequences resulting in cross-hybridization signals, they cannot be differentiated by centromere specific probes. Instead, these chromosomes can be identified by direct labeled Specific Probes hybridizing in close proximity to the respective satellite DNA sequences or to other chromosome specific loci.

The 13q12 Probe is designed to hybridize in close proximity of centromere 13 at 13q12.11. Since chromosomes 13 and 21 share the same repetitive sequences, they cannot be differentiated by probes detecting centromere specific repeats. The loss of chromosome 13q is associated with the RB1 (a tumor suppressor gene localized at 13q14) gene deletion occurring in approximately 30% of glioblastoma cases, but also in many other cancers. The use of the 13q12 probe together with other relevant markers (e.g. 1p36.3, 19q13, 9p21.3) is important in the complex diagnostics of malignant gliomas.