Molecular Genetic Tests

Molecular genetic tests look carefully at the genetic makeup (DNA) of cells and help pathologists confirm whether a lesion is the result of a cancerous or non-cancerous condition. One type of test is fluorescent in situ hybridization (FISH), which uses fluorescent dyes to identify chromosome abnormalities that are too small to be viewed under a microscope and specific gene changes in a cell. FISH is used on regular blood or bone marrow samples. Unlike standard cytogenetics testing, which may take two to three weeks to yield results, FISH provides accurate results in a matter of days. Another type is polymerase chain reaction (PCR), a highly sensitive DNA test that can detect changes too small to be visible under a microscope.