Chapter 3: Hair Analysis

Comparison microscope

Compound microscope that allows side by side comparison of samples such as hair or fibers

Cortex

Region of a hair located outside the medulla that contains granules of pigment

Cuticle

Tough outer covering of a hair that is composed of overlapping scales

Gas chromatography

Method of separating chemicals to establish their components

Hair follicle

The actively growing base of a hair that contains nuclear DNA and living cells

Isotope

Different forms of an element that differ in their atomic mass and number of neutrons

Isotope signature

(Isotope fingerprint) a ratio of different isotopes found in an individual

Isotope-ratio mass spectrometry (IRMS)

Technology that allows examiners to analyze ratio of isotopes each of oxygen, hydrogen, carbon, nitrogen, and sulfur

Keratin

Type of fibrous protein that makes up the majority of the cortex of a hair

Medulla

The central core of a hair medullary index the ratio of the medulla to the width of the hair

Melanin granules

Bits of pigment found in the cortex of a hair

Mitochondrial DNA (mtDNA)

Genetic material in the mitochondria of the cytoplasm of a cell; usually inherited from the mother

Nuclear DNA

Genetic material in the nucleus of a cell; inherited from the mother and father

Neutron activation analysis (NAA)

Process that relies on determining the concentrations of elements in materials by creating radioactive decay paths that can be identified and used to date archaeological specimens, gunshot residue, arsenic in hair, and geographic locations