Table 5.

A tentative assignment of the most important regions in the Raman spectrum of blood serum for the discrimination between AD and HC, as determined by the genetic algorithm (GA).

#	GA spectral region (cm−1)	Peak position (cm−1) +/− 5	Tentative band assignment [22, 23, 27, 55]	Contributions [22, 23, 27, 56, 57]
1	400-467	415, 419, 455	υ (C-C), υ (S-S), δ (C-C) aliphatic chains	Proteins (amino acids: histidine, tryptophan, lysine, proline); lipids (fatty acids, triglycerides, cholesterol); carbohydrates (fructose, lactose, citric acid, galactosamine, N-acetyl-glucosamine); riboflavin; phosphatidylinositol; phosphoenolpyruvate
2	505-523	509, 519, 526	υ(S-S)	Proteins (amino acids: glycine, glutamate, phenylalanine, tryptophan, tyrosine); carbohydrates (fructose, galactosamine, N-acetyl-glucosamine); coenzyme A; phosphatidylinositol; phosphatidylserine; acetoacetate; glutathione
3	993-1011	1003	υ(C-C), υ (C-O), Aromatics ring breathing vibration	Proteins (amino acids: phenylalanine, lysine, glutamate); carbohydrates (fructose, lactose, galactosamine, N-acetyl-glucosamine); acetoacetate
4	1030-1049	1031, 1050	υ(C-C), υ(C-O)	Proteins (amino acids: valine, arginine, phenylalanine, proline, glycine, lysine, tryptophan, tyrosine); carbohydrates (fructose, lactose, mannose); fatty acids; phosphoenolpyruvate; coenzyme A
5	1218-1237	1207, 1235	υ(C-C), υ(C-H), υ(C=S), (CH2) wagging vibrations	Proteins (β sheet, Amid III, tryptophan, tyrosine, lysine, phenylalanine, glycine, proline); pyruvate
6	1444-1462	1448	δ (CH2), δ(CH2OH), δ (CH3), υ(C-C)	Proteins (amino acids: valine, phenylalanine, tryptophan, lysine, proline); fatty acids; carbohydrates (fructose, galactosamine); phosphoenolpyruvate; acetoacetate; β-carotene; glutathione
7	1537-1556	1553	υ(N=N), υ(C=C), υ(C-(NO2))	Guanine; tryptophan; proline; palmitic acid; N-acetyl-glucosamine

^υstretching mode;

^δbending mode;