Molecular diagnosis is a technique used to detect specific sequences in DNA or RNA that may or may not be associated with disease, including single nucleotide polymorphism (SNP), deletions, rearrangements, insertions and others. The technique is used to diagnose and monitor disease, detect risk, and decide which therapies will work best for individual patients. The occurrence of molecular diagnostics is due to advances in biology that have resulted in an understanding of the mechanisms of normal and disease processes at the molecular level. Prior to this understanding, many disease states were diagnosed from morphologic observations. Molecular diagnostics can also be used to monitor a patient’s response to a specific drug treatment.