The 5p15, 9q34, 15q24 DNA-FISH Probe is designed to detect changes in copy number of chromosome(s) 5, 9, and 15 by fluorescence in situ hybrid­ization (FISH). Hyperdiploidy is characterized by increased copy numbers of chromosomes such that the modal chromosomal number is 47-57.It is ob­served in 30-50% of multiple myeloma (MM) cases where the most common trisomies involve chromosomes 3, 5, 7, 9, 11, 15, 19, and 21.^[1] In a diagnostic setting, gain of at least two of the three chromosomes 5, 9, or 15 in MM is considered an indicator for hyperdiploidy.^[2] When assessed by G-banded karyotype and in the absence of other aberrations such as IGH transloca­tions or deletion of chromosome 13, hyperdiploidy in MM is associated with a good prognosis.^[3-5]