Segmental hair analysis
Definition
The practice of cutting a hair strand into consecutive segments (typically 1 cm each) and analysing each segment separately. Because hair grows at roughly 1 cm per month, each segment represents approximately one month of systemic exposure, allowing a timeline of drug or toxin use to be reconstructed.
Related terms
- Anagen phase
- The actively growing phase of the hair follicle, during which the keratinocyte is in contact with the dermal papilla capillary and incorporates...
- External contamination
- The presence of a drug or substance on the outer surface of the hair shaft from environmental exposure rather than systemic ingestion....
- Hair shaft cortex
- The main structural layer of the hair shaft, composed of tightly packed keratin filaments. It contains the melanin granules responsible for hair...
- Mitochondrial DNA (mtDNA)
- DNA located in mitochondria rather than the cell nucleus. Present in hundreds to thousands of copies per cell, making it recoverable from...
- Short tandem repeat (STR)
- Short repetitive DNA sequences scattered throughout the genome, with the number of repeats varying between individuals at each locus. DNA profiling compares...
Explained in
- Hair as a Source of DNA and Toxicological InformationThe practice of cutting a hair strand into consecutive segments (typically 1 cm each) and analysing each segment separately. Because hair grows at roughly 1 cm...