Holographic optical trapping Raman micro-spectroscopy for interacting live cells

We present a combined holographic optical tweezers and confocal Raman spectroscopy instrument which allows fast, flexible, and interactive manipulation with molecular measurement of interacting live cell systems. Multiple laser foci created using a spatial light modulator are simultaneously used for optical trapping and spontaneous Raman spectroscopy. To enable confocal Raman measurements with high spectral resolution, a digital micro-mirror device was used to generate reflective pinholes which are matched to each laser trap. We demonstrate this unique capability by initiating complex interactions between multiple live cells whilst non-invasively acquiring Raman spectra of the processes with high spatial, spectral, and temporal resolution.