Figure 4

FTIRM spectra of the major cartilage components CII, proteoglycan and hyaluronan. (a) Typical spectra for CII, crude proteoglycan extract and hyaluronan. (b) An artificial spectrum that resembles normal articular cartilage generated by combining appropriate proportional amounts of the spectra of CII (55%), crude proteoglycan extract (40%) and hyaluronan (5%). The amide 1 peak from 1600–1700 cm^-1 represents the total protein content, the triplet of peaks from 1200–1300 cm^-1 are characteristic of the spectrum of collagen, and the peaks in the region 960–1175 cm^-1 result from sugars in the proteoglycans and hyaluronan.