Caption

Cryogenic storage of human tissue. Researcher removes a human tissue sample from liquid nitrogen storage for DNA (Deoxyribonucleic Acid) research. A metal box containing tissue samples is seen with the researcher using gloves and large forceps to remove an individual sample tube. The storage of such samples in liquid nitrogen (at -196 degrees centigrade) is known as cryogenics. Tissue samples such as umbilical cord and blood cells from relatives are stored. DNA extracted from these cells is used to study the progression of hereditary disorders such as Huntington's chorea or Haemophilia.