Typical hair/fiber analysis

o   http://www.chymist.com/FIBER%20ANALYSIS.pdf

o   http://www.fbi.gov/about-us/lab/forensic-science-communications/fsc/july2000/deedric1.htm

o   There is no exact procedure scientists use to analyze fiber, however, microscopic examination with longitudinal and cross sectional samples is a common method. Other tests such as burning, solubility, and color can also identify fiber (chymist.com). Similar to fiber analysis, hair analysis is usually done by light microscopy. This process involves two steps; first identify the questioned to hair and second to compare the questioned hair to the known hair. The identification of hair depends on how distinctive its properties are, which can be seen through comparison microscopy. Comparison microscopes have two compound light microscopes that are connected by an optical bridge that allow for the microscopic observation of two different hairs at the same time. It is hard to determine a statistical probability for a hair match because there is no exact way to quantitatively assess the microscopic characteristics in hair. To examine an unknown hair, first identify where it is from such as an animal or human then continue to analyze more specifically its type such as dog breed. Factors that affect analysis include experience, training, suitability of known hair standards, and adequacy of equipment (fbi.gov).

o     http://www.chem.sc.edu/analytical/chem107/lab4_032205.pdf
o     Similarly, hair evidences can be analyzed with microscopes using side-by-side comparison. This identify can classify race, region of body, length, color, and how the hair was removed. While it is unlikely that hairs from different people will look exactly the same under microscopic examination, it is possible. To be certain, hair evidence should examined through mtDNA sequencing because by it will verify that the identification of the hair is accurate. The drawbacks of mtDNA are that there is a greater cost, increased time period, it may not always be possible to completely extract DNA, there may not be enough tissue present, and the process destroys hairs. Thus it is important to still preform a microscopic examination and to consider all the factors involved with mtDNA sequencing.