Bacteria living near thermal vents on the ocean floor have yielded the second generation of heat-stable enzymes for use in the polymerase chain reaction (PCR). These are the first PCR enzymes to be derived from the sea. The PCR technique, developed with Federal funding, is used widely in biotechnology to amplify small quantities of DNA from clinical, environmental, and forensic samples. A small company in Massachusetts markets these ocean-derived enzymes as Vent® and Deep Vent® Polymerases.