Table 5 Potential spectral biomarkers for distinguishing active disease and disease remission using plasma samples based on the PLS-DA coefficients (ν = stretching; δ = bending).

From: Distinguishing active from quiescent disease in ANCA-associated vasculitis using attenuated total reflection Fourier-transform infrared spectroscopy

Wavenumber (cm−1) Tentative assignment Influence on AD
1778 ν(C = C) lipids
1748 ν(C = C) lipids
1716 ν(C = O) DNA/RNA
1701 ν(C = O) thymine
1662 Amide I
1509 In-plane δ(CH) phenyl ring
1481 Amide II
1408 δ(CH3)
1358 ν(C–O), δ(CH), δ(NH)
1230 νas(PO2)
948 Phosphodiester region (collagen and glycogen)
914 Phosphodiester region (collagen and glycogen)
1698 C2 = O guanine
1654 C = O, C = N, N–H of adenine, thymine, guanine, cytosine
1620 Base carbonyl stretching and ring breathing mode of nucleic acids
1558 Ring base mode
1415 CH deformation