Forensic DNA Testing Terminology

ABI 310 Genetic Analyzer – a capillary electrophoresis instrument used by
forensic DNA laboratories to separate short tandem repeat (STR) loci on the basis
of their size.
Adenine – a purine base; one of the four molecules containing nitrogen present in
the nucleic acids DNA and RNA; designated by letter A.
Allele – one of two or more alternative forms of a gene.
Allele Frequency – the proportion of a particular allele among the chromosomes
carried by individuals in a population.
ASCLD (ascld.org) – American Society of Crime Laboratory Directors; involved
with accreditation of DNA testing labs.
Amino acid – Any of a class of 20 molecules that are combined to form proteins in
living things. The sequence of amino acids in a protein and hence protein function
are determined by the genetic code.
Amplification – An increase in the number of copies of a specific DNA fragment;
can be in vivo or in vitro.
Autosome – A chromosome not involved in sex determination. The diploid human
genome consists of 46 chromosomes, 22 pairs of autosomes, and one pair of sex
chromosomes (the X and Y chromosomes).
Base pair – two complementary nucleotides in DNA; base pairing occurs between
A and T and between G and C.
Base sequence – the order of nucleotide bases in a DNA molecule.
Base sequence analysis – a method, sometimes automated, for determining the
base sequence.
Biotechnology – a set of biological techniques developed through basic research
and now applied to research and product development.
Blind proficiency test – a proficiency test in which the laboratory personnel do not
know that a test is being conducted.
Capillary electrophoresis – a method that utilizes a narrow polymer-filled tube to
separate DNA molecules by size.
Ceiling principle – a conservative approach for estimating a DNA profile’s
frequency of occurrence in a population containing multiple ethnic groups.
Chromosome – a large piece of DNA. Humans have 23 different chromosomes in
almost every type of cell.
CODIS – Combined DNA Index System, established in 1998 and containing the
STR DNA profiles of many thousands of convicted offenders.
COfiler – PCR Amplification Kit (AmpFLSTR® COfiler™) that provide human
identification laboratories with the ability to generate information for six STR loci
and Amelogenin.