In fact, 1 nanogram or less can produce unexceptional information for tracking down a suspect or victim of a crime. Using this technology, an investigator can expand their criminal investigation beyond the traditional realm of semen or dried blood. Crime scenes may contain DNA of lower value, this then depends on the environmental conditions in which the DNA was found. It is certain that a sequence of factors branches out the ability to obtain a satisfactory DNA profile. Regardless, prolonged exposure to any type of biological evidence can degrade DNA and therefore render it useless for further analysis. DNA, deoxyribonucleic acid (DNA) are the molecules that carry the genetic information of a living being. At a disadvantage, the medical examiner's only options were to focus on blood factors such as A, B, and O as the only way to connect a suspect to the crime. Plasma is the liquid part of blood and blood refers to the complex mixture of proteins, cells, enzymes and inorganic materials. DNA testing is a method used to study collective variation. Each method is unique and has its own limitations and variations and may have different technical characteristics.