HOSA Forensic Science: DNA Analysis

Amplicons

Product of the amplification of DNA or RNA

Annealing

Pairing of complementary strands of dot blot DNA analysis. (When two strands return together after denaturation due to the forces of hydrogen bonding)

Capillary Electrophoresis

An instrumental technique that is used in DNA typing. Involves a tiny electrophoresis in which gel fragments are separated and detected by laser-induced fluorescence.

Denaturation

Loss of the natural configuration of a molecule through heat, chemical treatment or pH change

DNA polymerase

Enzymes that break the linkage within the double helix

Flanking Region

Region just adjacent to a region of interest, a gene, a repeat, or any other sequence

Heterogeneous

Two different alleles at a specific genetic locus

Homozygous

Both alleles are the same at a specific genetic locus

Hyper-variable Regions

Locus with many alleles, especially those whose variation is due to variable numbers of tandem repeats

mtDNA

DNA found in the mitochondria, a circular duplex with a genetic code differing from the universal genetic code

Microsatellites

Short, tandem repeat or simple sequence length polymorphisms composed of di-, tri-, tetra- or pentanucleotide repeats. Basically its a strand of DNA with short sections that are repeated over and over again.

Minisatellites

Simple sequence tandem repeat polymorphisms in which the core repeat unit is usually 10 to 50 nucleotide long; variable number of tandem repeats

Mitochondria

An energy-producing structure within a cell that contains DNA. It is not the same as the DNA that is found in the nucleus of the cell

Nucleases

Enzymes that break down DNA

Polymerase Chain Reaction

A reaction used to make copies of segments of DNA. Involves the use of heat to denature the DNA and bacterial DNA polymerase to copy the DNA.

Satellite DNA

Highly repetitive eukaryotic DNA located primarily around centromeres and found in places other than the genome.

Short Tandem Repeats

A simple short sequence of DNA that contains a repeated pattern of nucleotides

Tetramers

Repeats of four base pairs

Variable Number Tandem Repeats

Chromosomal locus at which a particular repetitive sequence is present in different numbers in different individuals of a population; a simple sequence tandem repeat polymorphous in which the core repeat unit is usually 250 bases long.

Short Tandem Repeats

DNA analysis typically looks at what regions of the genome?