NCJ Number
196570
Journal
FBI Law Enforcement Bulletin Volume: 71 Issue: 8 Dated: August 2002 Pages: 16-22
Date Published
August 2002
Length
7 pages
Annotation
After explaining the science of mitochondrial DNA (mtDNA), this article describes steps in mtDNA analysis and quality assurance in mtDNA testing.
Abstract
Found in almost every cell in the human body, DNA contains the information that enables the body to function and gives everyone a unique appearance. DNA can be found in two separate locations within most cells in the body. Nuclear DNA is found in the nucleus of the cell. Two copies of nuclear DNA are found in each cell, one copy from the father and one copy from the mother. Mitochondrial DNA differs from nuclear DNA in its location, its quantity in the cell, its mode of inheritance (only from the mother), and its sequence. Mitochondrial DNA is located in structures, called mitochondria, found in the outer layer of the cell. Cells may contain hundreds of mitochondria, each of which may contain several copies of mtDNA. Thus, mtDNA has a greater copy number than nuclear DNA. This characteristic of mtDNA proves useful in situations in which the amount of a sample is very limited. Typical sources of evidence suitable for mtDNA analysis include hairs without tissue, bones, and teeth. The description of steps in mtDNA analysis encompass primary visual analysis, sample preparation, DNA processing, and data analysis. A description of the FBI's procedure for quality assurance in mtDNA testing notes that the FBI Laboratory uses positive and negative controls in mtDNA processing to monitor amplification and sequencing and does not proceed with the mtDNA analysis if these controls fail to meet established criteria. 7 notes