Forensic Bio Unit 3

Fluorophore

The component of a fluorescent dye that fluoresces upon excitation by light.

Stokes Shift

The difference in wavelength between the excitation and emission of a fluorophore.

Singleplex PCR

A PCR method using one primer set to amplify a single region of interest.

Multiplex PCR

A PCR technique that allows the amplification of multiple regions concurrently, using multiple primer sets.

RFLP

Restriction Fragment Length Polymorphism, a method for analyzing VNTRs without PCR, requiring larger DNA amounts.

VNTR

Variable Number Tandem Repeats; regions of repeated sequences in DNA that can vary in length.

AFLP

Amplified Fragment Length Polymorphism, a PCR-based technique for assessing VNTRs.

STR

Short Tandem Repeats; a type of microsatellite used for DNA profiling that consists of short repeat units.

Electrophoresis

A laboratory technique used to separate DNA fragments based on size.

Core CODIS loci

The selected loci used by the Combined DNA Index System for forensic DNA profiling.

Stutter

An artifact during PCR where the produced DNA fragment is one repeat short or long due to slippage.

Null allele

An allele that fails to amplify during PCR due to mutations in the primer binding site.

Heteroplasmy

The presence of different mtDNA haplotypes within a single individual.

Cycling sequencing

A technique that uses repeated thermal cycling to produce labeled DNA fragments for sequencing.

Y-STR

Y-chromosome Short Tandem Repeats, useful for tracing paternal lineage and in cases of male DNA mixtures.

Bilocal Y-STR

A Y-STR profile that exhibits two alleles, due to duplication despite having only one Y-chromosome.

Rapidly Mutating Y-STRs

A subset of Y-STRs with higher mutation rates allowing for differentiation between closely related males.

Allelic ladder

A sample containing known alleles used for determining the size of PCR fragments in genotyping.

Mixture interpretation

Analyzing DNA profiles that contain contributions from two or more individuals.

Degraded DNA

DNA that has broken down into smaller fragments, often impacting PCR amplification results.

Internal Lane Standard (ILS)

A reference added to each sample to help identify and size the fragments in electrophoresis.