Peak position (cm−1)

Vibrational mode

Proposed primary source

Leukoplakia tissue

Cancer/normal tissue

1024

1030

C-O streching, C-O bending

glycogen

1238

1238

PO2-stretching

nucleic acid

1388

1388/1390

CH2 bending

protein

1454

1451

CH2 bending

protein

1535

1535

amide II: CN-H, C-N

protein

1650

1650

amide I: C=O streching

protein