text: DNA extraction is frequently a preliminary step in many diagnostic procedures used to identify environmental viruses and bacteria and diagnose illnesses and hereditary diseases. These methods consist of, but are not limited to:
  Fluorescence In Situ Hybridization (FISH) technique was developed in the 1980s. The basic idea is to use a nucleic acid probe to hybridize nuclear DNA from either interphase cells or metaphase chromosomes attached to a microscopic slide. It is a molecular method used, among other things, to recognize and count particular bacterial groupings.
  To recognize, define, and quantify the geographical and temporal patterns in marine bacterioplankton communities, researchers employ a technique called terminal restriction fragment length polymorphism (T-RFLP).
  Sequencing: Whole or partial genomes and other chromosomal components, ended for comparison with previously published sequences.