12 chromosome centromere (CEP12) labeled as orange.
Overview
CEP12 probe (Chromosome Enumeration Probe 12) is used to identify and count the number of copies of chromosome 12 in a cell, by targeting the highly repetitive alpha-satellite DNA sequences located at the centromere (specifically the 12p11.1-q11.1 or D12Z3 locus). CEP12 is a basis in the diagnostic work out for Chronic Lymphocytic Leukemia (CLL), as trisomy 12 is one of the most common genetic abnormalities in in trisomy.