DNA Fingerprinting

Forensic Science DNA Unit

Allele

an alternate form of a gene

Chromosome

a cell structure that contains the genetic information along strands of DNA

DNA fingerprint

pattern of DNA fragments obtained by examining a person's unique sequence of DNA base pairs

electrophoresis

method of separating molecules, such as DNA according to their size and electrical charge using an electric current passed through a gel containing the samples

gene

segment of DNA in a chromosome that contains information used to produce a protein or an RNA molecule.

PCR (polymerase chain reaction)

a method used to rapidly make multiple copies of a specific segment of DNA; can be used to make millions of copies of DNA from a very small amount.

restriction enzyme

a molecule that cuts a DNA molecule at a specific base sequence

STR (short tandem repeats)

repeats of short DNA sequences (2 to 5 base pairs) with varying number of repeats found among individuals

VNTR (variable number of tandem repeats)

repeats of short DNA sequences (9 to 80 base pairs) with varying number of repeats found among individuals

Genome

total amount of DNA in a cell

Polymorphisms

differences in DNA sequence from person to person

Exons

DNA that codes for a protein

Introns

DNA that does not code for a protein

RFLP (restriction fragment length polymorphisms)

variation in the length of fragments produced by a restriction enzyme in a sample of DNA

mtDNA

DNA located in the mitochondria

nDNA

DNA located in the nucleus

CODIS

the United States electronic database of DNA profiles