Vibrational Spectroscopy and Cancer - Vibrational Spectroscopy for Tissue Analysis - page 93

Chan et al. worked on detection of individual neoplastic and normal
hematopoietic cells using micro-Raman spectroscopy. The potential applica-
tion of confocal micro-Raman spectroscopy as a clinical tool for single-cell
cancer detection based on intrinsic biomolecular signatures was demon-
strated. They showed that this method can discriminate among different
kinds of unfixed lymphocytes, and single-cell Raman spectra provide a
highly reproducible biomolecular fingerprint of each cell type. Characteristic
peaks, mostly due to different DNA and protein concentrations, allowed for
discerning normal lymphocytes from transformed ones with high confi-
dence (p << 0.05). The method was shown to have a sensitivity of 98.3% for
cancer detection, with 97.2% of the cells being correctly classified as belong-
ing to the normal or transformed type [167].
Bogomolny et al. analysed the early spectral changes accompanying malig-
nant transformation of cells in culture by FTIR microspectroscopy [168]. The
cells were infected by the murine sarcoma virus (MuSV), which induces
malignant transformation, and the spectral measurements were taken at
various postinfection time intervals. The results indicate that the first spec-
tral changes are detectable much earlier than the first morphological signs
of cell transformation. It was found out that the first spectral signs of malig-
nant transformation are observed on the first and third day of postinfection,
while the first visible morphological alterations are observed only on the
third and seventh day, respectively.

Analysing Saliva
Interestingly, Raman has been successfully used to study saliva and there have
been a number of studies reported in the literature (Table 4.14). Farguharson
et al. measured the chemotherapeutic drug 5-fluorouracil in saliva using
SERS. A silver-doped sol-gel provided SERS and also some chemical selec-
tivity. 5-fluorouracil and physiological thiocyanate produced SERS, whereas
large biochemicals, such as enzymes and proteins, did not, supporting the
expectation that the larger molecules do not diffuse through the sol-gel to
any appreciable extent. In addition, 5-fluorouracil samples of 2 µgml −1 were
easily measured, and an estimated limit of detection of 5 µgml −1 in 5 minutes
should provide sufficient sensitivity to perform pharmacokinetic studies
and to monitor and regulate patient dosage [169].

Table 4.14
Article on Saliva

Research
Method

Investigated
Tissue or Sample

Effectiveness of
the Technique

Reference
Number Research Group

Farguharson et al. Raman Saliva + 169