Fig. 5.

Intracellular localisation of alkyne tagged fatty acids. False colour images of the peak maximum intensity of the Raman signal at 1448 cm⁻¹ divided by the sum of the peak intensities of the Raman signals at 1448 cm⁻¹ and 1657 cm⁻¹ for Raman maps of HEK293T cells incubated for 4 h with 100 μM C14 alkyne (a), for 4 h with 100 μM C16 alkyne (b) and for 4 h with 100 μM C18 alkyne (c). These images (blue) were overlaid with the respective false colour images of the intensity of the alkyne stretching peak at 2118 cm⁻¹ (red) for C14 alkyne (d), C16 alkyne (e) and C18 alkyne (f) and regions attributed to nuclei were highlighted using black outline. Maps were acquired using a step size of 1 μm in x and y, 532 nm excitation, 100%/ca. 20 mW laser power, 1 s acquisition time and a spectral centre of 2000 cm⁻¹. False colour image numbers on axis represent microns.