The Cytomegalovirus (CMV) BioProbe® labeled probe is prepared by nick translation of cloned fragments of the CMV Towne strain. The fragments include a total of 30-31 kb of DNA, approximately 20% of the CMV genome. The probe is specific for cytomegalovirus DNA. It does not hybridize to DNAs of other herpesviruses (i.e., herpes simplex virus or Epstein-Barr virus) but it has been found to hybridize to the DNA of CMV clinical isolates. Fragment size range: 100-1000 base pairs (as estimated by agarose gel electrophoresis).