Dual beam fibre trap for Raman micro-spectroscopy of single cells

Area of Science:

• Biophysics
• Spectroscopy
• Cell Biology

Background:

• Raman spectroscopy provides molecular signatures from cellular samples.
• Optical trapping isolates cells for analysis, but struggles with large cells.
• Existing methods use single beam optical tweezers with Raman spectroscopy.

Purpose of the Study:

• To develop an improved optical trapping system for manipulating large cells.
• To combine dual beam fiber trapping with Raman spectroscopy for detailed cellular analysis.
• To demonstrate the system's capability with primary human keratinocytes and leukemia cells.

Main Methods:

• Utilized a dual beam fiber trap for cell manipulation.
• Employed an orthogonally placed objective for Raman spectra acquisition.
• Integrated a microfluidic system for cell flow and selection.

Main Results:

• Successfully held and maneuvered large primary human keratinocytes (approx. 30 microns).
• Acquired Raman spectra from localized regions of trapped cells with ease.
• Demonstrated selective spectral acquisition from individual HL60 leukemia cells in flow.

Conclusions:

• The dual beam fiber trap effectively holds and maneuvers large cells with reduced photodamage.
• This system enables high-resolution Raman spectroscopy of specific cellular regions.
• The combined trapping and microfluidic system facilitates analysis of individual cells from a population.