Forensic DNA Analysis Overview and Applications

Forensic DNA Analysis

Study of DNA for legal evidence.

DNA Typing

Process of identifying individuals using DNA.

Criminal Casework

Comparing suspect's DNA with crime scene evidence.

Paternity Testing

Determining biological relationships for legal purposes.

Mass Disasters

Using DNA for victim identification in tragedies.

Historical Investigations

Analyzing DNA from historical artifacts or remains.

CODIS Database

Stores DNA profiles of convicted offenders.

Unique Genome

Each individual has distinct DNA, excluding twins.

Nuclear DNA (nDNA)

46 chromosomes inherited from both parents.

Mitochondrial DNA (mtDNA)

Circular DNA inherited only from the mother.

Sequence Polymorphisms (SNPs)

Variations in single nucleotides at specific locations.

Length Polymorphisms (STRs)

Variations in short tandem repeats of nucleotides.

Evidence Collection

Gathering biological materials containing DNA.

Serology Testing

Identifying biological fluids using presumptive tests.

DNA Extraction

Isolating DNA from biological materials.

DNA Quantification

Determining amount and quality of DNA present.

DNA Amplification (PCR)

Amplifying specific DNA regions for analysis.

Capillary Electrophoresis

Separating DNA fragments by size and color.

Genotyping

Determining alleles at specific STR loci.

Match/Inclusion

DNA profiles match at all loci examined.

Exclusion

DNA profiles do not match.

Inconclusive

DNA is degraded or mixed, results unclear.

Random Match Probability

Estimates likelihood of identical DNA profiles.

Population Allele Frequencies

Used to calculate random match probability.

Combined DNA Index System (CODIS)

National database for storing DNA profiles.

Convicted Offenders

Individuals with DNA profiles stored in CODIS.

Arrestees

Individuals arrested whose DNA may be stored.

Forensic Unknowns

DNA profiles from crime scene samples.

Electropherograms

Graphical representation of DNA profiles.

DNA Integrity

Preservation and proper collection are crucial.

Statistical Analysis

Ensures reliability of DNA match results.

Genetic Genealogy

Using DNA for ancestry and criminal investigations.

Advancements in Sequencing

Improving forensic capabilities through technology.

Degraded Samples

Samples that have lost DNA quality.

Biological Materials

Sources of DNA like blood, saliva, and hair.

Presumptive Tests

Initial tests for detecting biological fluids.

Confirmatory Tests

Tests that confirm presence of biological materials.

Time Complexity

Forensic analysis takes longer than portrayed in media.