Forensic DNA Analysis

Vocabulary flashcards related to techniques and case studies in forensic DNA analysis.

DNTR

Variable number of tandem repeats. Looks at sizes of DNA using PCR and examines larger regions with 10 to 100 base repeats.

Restriction Enzymes

Cuts DNA to look at sizes and number of specific restriction sites in the DNA, requires a lot of DNA.

STRs

Short tandem repeats. Based on microsatellites with two to six base repeats, utilizes PCR for amplification.

Microsatellites

Small DNA repeats found mostly in euchromatin, easily accessible. STRs are based on these.

CODIS

Combined DNA Index System. National DNA repository established in 1998 storing DNA evidence from crime scenes and arrestees. Based on STR analysis.

Loci (in CODIS context)

Refers to the location on a chromosome where microsatellites are located, not necessarily referring to a gene.

Amelogenin

A gene located on both X and Y chromosomes but has a six base pair deletion on the X chromosome, used for sex determination in DNA profiling.

Heterozygous

Having two different alleles or repeat numbers at a particular locus, resulting in two peaks in a DNA profile.

Homozygous

Having the same allele or repeat number on both chromosomes at a particular locus, resulting in one peak in a DNA profile.

Partial Match (Familial Match)

A CODIS profile that shares some, but not all, of the 13 loci, indicating a familial relationship.

BTK Killer Case

Dennis Rader, a serial killer identified through partial CODIS match to his daughter's DNA from a Pap smear, and DNA genealogy.

Mitochondrial DNA Analysis

Analysis of DNA inherited through the maternal line, used when limited or degraded DNA is available.

Forensic Genealogy

Using genealogy databases to identify potential suspects through familial DNA matches.

DNA Phenotyping

Using genetic information to predict physical appearance (e.g., skin color, eye color, hair color) of an individual.

SNPs

Single Nucleotide Polymorphisms. Differences at a single nucleotide within a DNA sequence. Used to generate DNA phenotypes.