Dual-trap Raman tweezers for probing dynamics and heterogeneity of interacting microbial cells.

We report on development of dual-trap Raman tweezers for monitoring cellular dynamics and heterogeneity of interacting living cells suspended in a liquid medium. Dual-beam optical tweezers were combined with Raman spectroscopy, which allows capturing two cells that are in direct contact or closely separated by a few micrometers and simultaneously acquiring their Raman spectra with an imaging CCD spectrograph. As a demonstration, we recorded time-lapse Raman spectra of budding yeast cells held in dual traps for over 40 min to monitor the dynamic growth in a nutrient medium.

[Using Raman spectroscopy to analyze apoptosis of gastric cancer cells induced by cisplatin].

Apoptosis of gastric cancer cells induced by cisplatin was investigated using laser Raman spectroscopy. Gastric cancer cells (SGC7901) were treated with 10 microg x mL(-1) cisplatin for 24, 48 and 72 hours, then were divided into two parts, one for fluorescence staining, the other for collection of Raman spectra by means of scanning. The acquired spectra were then preprocessed by background elimination, smoothing, normalization, baseline correction, and peak fitting.

[The effect of abnormal cell shape on the spectral distinguishing of erythrocytes using laser tweezers Raman spectroscopy].

Erythrocyte is a mature blood cell that contains hemoglobin to carry oxygen to the bodily tissues. Erythrocyte, which takes on a biconcave disc that has no nucleus, is flexible and changeful. Erythrocyte is so sensitive to the environment that the shape of cell goes crimpy, even acanthoid.

[Laser tweezers Raman spectroscopy analysis of liver cancer tissue].

Single cell laser tweezers Raman spectroscopy (LTRS) has been applied to biology field. In the present article, the authors measured the spectra of liver cancer cells, para-cancer cells and normal hepatocytes using single cell laser tweezer Raman spectroscopy (LTRS) system and compared their average spectra changes. The results showed that the laser tweezers Raman spectroscopy could differentiate specimens of different pathological changes from liver tissue studied.

[Study of Raman spectra of single carcinoma of nasopharynx cell].

The Raman spectra from carcinoma of nasopharynx cell lines (CNE2) and normal airway epithelial cell lines (HBE) were investigated using a laser tweezers Raman spectroscopy (LTRS). The Raman scattering measurements were obtained from three different places in every single cell. Visual inspection of the spectra shows that the differences observed in spectra of the cancer cells and normal cells are obvious.

[Raman micro-spectroscopy of single blood platelets].

The authors collected the Raman spectra of single blood platelets of human, pig, rat and rabbit suspended in saline so-lution by using a laser tweezers Raman spectroscopy (LTRS) setup. A single platelet cell was trapped in the focus of a near-infrared laser beam at 785 nm and the excited Raman spectrum was acquired. For each species, the Raman spectra of up to 20 platelet cells were acquired and were used to perform a principal components analysis (PCA) or a discriminate function analysis (DFA).