Resonance Raman Probes for Organelle-Specific Labeling in Live Cells.

Andrey N Kuzmin,Ken-Tye Yong,Artem Pliss,Alexander Rzhevskii,Jeongyun Heo,Paras N Prasad,Bobo Gu,Chang-Keun Lim,Sehoon Kim,Shuangchun Wen

doi:10.1038/srep28483

Abstract

Raman microspectroscopy provides for high-resolution non-invasive molecular analysis of biological samples and has a breakthrough potential for dissection of cellular molecular composition at a single organelle level. However, the potential of Raman microspectroscopy can be fully realized only when novel types of molecular probes distinguishable in the Raman spectroscopy modality are developed for labeling of specific cellular domains to guide spectrochemical spatial imaging. Here we report on the design of a next generation Raman probe, based on BlackBerry Quencher 650 compound, which provides unprecedentedly high signal intensity through the Resonance Raman (RR) enhancement mechanism. Remarkably, RR enhancement occurs with low-toxic red light, which is close to maximum transparency in the biological optical window. The utility of proposed RR probes was validated for targeting lysosomes in live cultured cells, which enabled identification and subsequent monitoring of dynamic changes in this organelle by Raman imaging.

Highlights

Live cells where lysosomes were labeled with both BBQ650-Lyso and commercial fluorescent lysotracker, were imaged by the multimodal imaging system described in our earlier publications[3,15]
We introduced a generation of Raman probe for labelling organelles in live cells that utilizes a BBQ650-NHS structure
A valuable feature of this probe is that the resonance excitation is achieved using biologically safe light wavelengths in the red region enabling non-invasive live cell imaging

Summary

Introduction

Live cells where lysosomes were labeled with both BBQ650-Lyso and commercial fluorescent lysotracker, were imaged by the multimodal imaging system described in our earlier publications[3,15]. For imaging using fluorescent lysotracker, 10 μW excitation at 532 nm was used in combination with a 60 nm band-pass optical filter centered at 580 nm (FF01-580/60, Semrock, USA). The RR signal of BBQ650-Lyso, generated by 30 mW of 633 nm excitation, was used for imaging, employing a 30 nm band-pass optical filter centered at 687 nm

Methods

Results

Conclusion