We report on a novel technique for sorting and identification of single biological cells and food-borne bacteria based on laser tweezers and Raman spectroscopy (LTRS). With this technique, biological cells of different physiological states in a sample chamber were identified by their Raman spectral signatures and then they were selectively manipulated into a clean collection chamber with optical tweezers through a microchannel. As an example, we sorted the live and dead yeast cells into the collection chamber and validated this with a standard staining technique. We also demonstrated that bacteria existing in spoiled foods could be discriminated from a variety of food particles based on their characteristic Raman spectra and then isolated with laser manipulation. This label-free LTRS sorting technique may find broad applications in microbiology and rapid examination of food-borne diseases.
© 2005 Optical Society of America
(120.3890) Instrumentation, measurement, and metrology : Medical optics instrumentation
(170.1530) Medical optics and biotechnology : Cell analysis
(170.5660) Medical optics and biotechnology : Raman spectroscopy
Changan Xie, De Chen, and Yong-qing Li, "Raman sorting and identification of single living micro-organisms with optical tweezers," Opt. Lett. 30, 1800-1802 (2005)