1. Discriminating Basal Cell Carcinoma from its Surrounding Tissue by Raman Spectroscopy 
Tom C. Bakker Schut, Peter J. Caspers, Gerwin J. Puppels, Dr 
Journal of Investigative Dermatology 
Volume 119, Issue 1, Pages (July 2002)
DOI: /j x
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

2. Figure 1
Two-step classification model using logistic regression. The database of Raman spectra obtained from BCC, dermis, and epidermis was used as input for the classification model. The first logistic regression model distinguishes dermis from BCC and epidermis. The second model separates epidermis and BCC.
Journal of Investigative Dermatology  , 64-69DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

3. Figure 2
Comparison of microscopic image of BCC and pseudo-color Raman map with corresponding Raman spectra. Pseudo-color Raman map, based on Raman spectra obtained from a frozen tissue section of BCC. A Raman spectrum was obtained for each 10 × 10 µm2 pixel. KCA yielded two clusters corresponding to BCC and surrounding dermis as follows from a comparison with (b). H&E-stained thin section adjacent to the section used in the Raman experiment, showing nodular BCC (b1) and its surrounding tumor-free dermis (b2). The area shown corresponds to the area scanned in the Raman experiment. Cluster averaged Raman spectra from BCC (c1) and dermis (c2). To enhance the characteristic spectral features of BCC a difference spectrum BCC dermis (c3) was calculated. The dashed lines indicate bands in the difference spectrum that can be attributed to fatty acid represented here by oleic acid (c4) and DNA (c5).
Journal of Investigative Dermatology  , 64-69DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

4. Figure 3
Comparison of pseudo-color Raman maps with images of H&E-stained adjacent sections. (a,b) BCC and surrounding dermis: Clustering analysis of the Raman spectra distinguishes BCC, dermis directly surrounding the tumor and dermis at a greater distance from the tumor. (c,d) KCA again distinguishes BCC, dermis directly surrounding the tumor and dermis at a greater distance from the tumor. Furthermore, a dense inflammatory infiltrate is present and detected by Raman spectroscopy. Black = BCC; red = dermis close to tumor; green = dermis at a greater distance from tumor; blue = dense chronic inflammatory infiltrate. 1 = BCC; 2 = collagen-poor dermis; 3 = collagen-rich dermis; 4 = chronic inflammatory infiltrate. Scale bar: 100 μm.
Journal of Investigative Dermatology  , 64-69DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

5. Figure 4
Raman spectra of the dermis adjacent to BCC. (a) Raman spectrum from dermis at a greater distance from the tumor; green area in Figure 3(a). (b) Raman spectrum obtained from dermis directly surrounding the tumor; red area in Figure 3(a). (c) Raman spectrum obtained from dermis with a dense chronic inflammatory infiltrate; blue area in Figure 3(c). (d) Difference spectrum a–b. (e) Difference spectrum a–c. (f) Raman spectrum of pure collagen type 1. (g) Difference spectrum c–a. (h) Raman spectrum of oleic acid. Note the strong resemblance between the spectra d, e, and f as well as g and h. For clarity of presentation the difference spectra were magnified by a factor 1.5.
Journal of Investigative Dermatology  , 64-69DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions

6. Figure 5
Comparison of pure DNA to a difference spectrum of BCC and epidermis. (a) Raman spectrum of BCC. (b) Raman spectrum of epidermis. (c) To enhance the differences between the two spectra (a,b), a difference spectra (a,b) were calculated. For clarity of presentation the difference spectrum was magnified by a factor 2.0. (d) DNA–Raman spectrum. Prominent and characteristic DNA–Raman bands are present in the difference spectrum BCC–DNA (c).
Journal of Investigative Dermatology  , 64-69DOI: ( /j x)
Copyright © 2002 The Society for Investigative Dermatology, Inc Terms and Conditions