Figure 1.

Examples of “positive” (for breast cancer) and “negative” (for breast cancer) hair fibre X-ray diffraction patterns. The raw diffraction data was processed and resulting images were generated using SAXS-15ID as described in the text. A) the pattern from a “negative” hair fibre. No circular feature is present, as confirmed by the plot. Note the presence of intense arcs, particularly in the equatorial plane. These are diffraction features regularly observed for α-keratin. B) the pattern produced from a hair fibre from a woman with breast cancer. Note the circular feature (arrowed) passing through the equatorial spots, at a q space of 1.32 nm⁻¹ as defined by the accompanying one-dimensional plot. The other α-keratin features are present at similar intensities to those observed in A.