Stout P R, Ropero-Miller J D, Baylor M R, Mitchell J M
Center for Forensic Sciences, RTI International, Research Triangle Park, NC 27709, United States.
Forensic Sci Int. 2007 Oct 25;172(2-3):164-70. doi: 10.1016/j.forsciint.2007.01.011. Epub 2007 Feb 22.
Morphological changes in hair subjected to decontamination protocols were evaluated by scanning electron microscopy (SEM) as part of the National Laboratory Certification Program's (NLCP) efforts to develop proficiency testing materials in support of Federal Workplace Drug Testing programs. Hair from five different donors was evaluated. Hair samples were subjected to three decontamination protocols: (1) aqueous phosphate buffer, (2) methanol or (3) methylene chloride as models for aqueous, alcohol and polar organic solvent protocols, respectively. Under these protocols, samples of hair were treated for 225 min (aqueous), 15 min (alcohol), or 15 min (polar organic). After decontamination, hair strands were sputter coated with gold/palladium (AuPd) and observed by SEM. Modest lifting of cuticle scales was observed in hair treated with methanol and methylene chloride consistent with some changes to the cell membrane complex (CMC) between cuticle scales. Damage resulting from aqueous buffer treatment ranged from substantial degradation to apparent complete loss of cuticle scales. Fracture structures consistent with cuticle damage were also observed. Each decontamination protocol had a different impact on the cuticle of the hair shaft.
