Images of healthy human hair. C. Michael Smith Images of healthy human hair. Microscope images of 2-3 micron cross-sections of hair from one individual Hair samples were embedded in OCT and cut at -10°C. The OCT was then washed away, leaving the cross sections of hair suspended in water.

Representative IR Spectrum of Healthy Human Hair C. Michael Smith Representative IR Spectrum of Healthy Human Hair Absorbance / Wavenumber (cm-1)

Longitudinal Sections of Healthy Human Hair C. Michael Smith Longitudinal Sections of Healthy Human Hair 2-3 µm longitudinal section of hair embedded and cut in paraffin 2-3 µm longitudinal section of hair embedded and cut in OCT.

IR Spectrum of Healthy Human Hair with Expected Lipid Peak C. Michael Smith IR Spectrum of Healthy Human Hair with Expected Lipid Peak Absorbance / Wavenumber (cm-1)

Figure 2. Infrared spectrum from one specific point (shown in the inset figure, top right), in the 3000 cm-1 vibrational region. The small peaks are mostly due to lipid stretching vibrations. These features show significant variation from site to site in the hair sample.

Figure. X-ray diffraction pattern from patient #1. Diffuse “lipid” ring can be seen.

Conclusions IR data and x-ray are consistent. Lipid domains appear to be increased in the cortex, just inside the cuticle and away from the medulla. X-ray & IR data appear to show significant variation. HOWEVER, the sample size of 5 is too small for a definitive conclusion. Recommendation: Extend the studies to ~20 samples, with BOTH IR and X-ray studies (Cornell) over the summer.