Table 6.

Tentative assignments of the major vibrational modes for IR and Raman spectroscopy

		Top six discriminating wavenumbers with tentative biochemical assignments
Comparisons		ATR FTIR spectroscopy		Raman spectroscopy
Normal vs. meningioma	1018	Glycogen	≈ 911	C–C stretching of proline ring/glucose/lactic acid
	1173	Carbohydrate	≈ 964	Lipids, proteins (CH3 deformations)
	1543	Amide I	≈ 1237	Amide III
	1582	Amide II	1276	Amide III (α-helix)
	1620	Amide I	1485	Lipids and proteins (CH2 deformation), purine ring(guanine)
	1740	Lipids	1655	Amide I/lipids
Normal vs. LA	1103	νasPO2−	800	Undefined
	1234	νasPO2−	903	Undefined
	1470	CH2 bending of the methylene chains in lipids	≈ 999	Glucose-I-phosphate and symmetric ring breathing mode of phenylalanine
	1504	Amide II	1306	Lipids, collagen, protein amide III, DNA purine bases, phenylalanine
	1628	Amide I	1446	Proteins and lipids (CH2 bending mode of proteins and lipids)
	1686	Amide I	1670	Cholesterol esters, Amide 1
Normal vs. AA	1018	Glycogen	810	Undefined
	1234	Asymmetric phosphate	853	Tyrosine, proline, glycogen
	1489	In-plane CH bending vibration	911	C–C stretching of proline ring/ glucose/lactic acid
	1551	Amide II	1004	Lipids and proteins, phenylalanine
	1628	Amide I	≈ 1455	Protein δ (CH2/CH3)
	1701	Lipid	1670	Cholesterol esters, Amide 1
Normal vs. GBM	1107	Glycogen	≈ 849	Tyrosine and proline, glycogen
	1393	COO- symmetric stretching	904	Undefined
	1474	Proteins?	≈ 917	C–C stretching, glycogen, lactic acid
	1531	Amide II, Modified guanine?	1001	Phenylalanine (symmetric ring breathing mode)
	1585	Amide I	≈ 1473	CH2 deformation
	1659	Amide I	1673	Lipids, Amide I
Normal vs. metastasis	1173	Carbohydrate	≈ 997	Phospholipids, glucose-I-phosphate
	1489	In-plane CH bending vibration	1077	Lipids (C–C vibrations)
	1543	Amide II	1241	Amide III
	1632	Amide I	1446	Proteins and lipids (CH2 bending mode of proteins and lipids)
	1659	Amide I	≈ 1460	Cytosine
	1740	C=O stretching (lipids)	1654	Amide I (C=O stretching mode of proteins, α-helix conformation)/C=C lipid stretch