Journal: The Journal of Biological Chemistry

Article Title: Insights into chlamydial infection at the sub-cellular level using label-free Raman spectroscopy in comparison to electron microscopy

doi: 10.1016/j.jbc.2025.110940

Figure Lengend Snippet: Analysis of 3D Raman image stacks of infected BGM cells at time points 18, 36, 48 and 54 h post infection (p.i.) . A , bright field overview images of BGM cells infected with C . abortus at different hours p.i. The red square highlights the region (10 μm × 10 μm) that was further analyzed by Raman spectroscopic imaging. This scale bar represent 10 μm. B , false color Raman images of the three z-planes measured in the region highlighted in panel A . Blurring filter and 3D perspective were applied for better visualization. The color code is the same throughout the panels B – D : white - PBS/water, orange - DNA/nucleus, dark red - RB of C . abortus , mid blue - EB of C . abortus , light green - cytoplasm of the host cell. The false color image is a superposition of the relative abundance of each endmember in each pixel. The scale bars represent 1 μm. The distance between z-layers is 1 μm. C , gray-scale maps showing abundance distributions of C . abortus endmembers in the middle layer shown in panel B . Color gradients were corrected to make lower values more visible. D , endmember spectra corresponding to the abundances shown in panels B and C . For C . abortus , the spectra are overlaid with the corresponding endmember spectrum of isolated bacteria from I for comparison. The spectra of isolated C . abortus are upscaled to simplify visual comparison. Original values are provided in I . , and provide the same information for all eight Raman images without additional effects. BGM, buffalo green monkey; EB, elementary body; RB, reticulate body.

Article Snippet: Intact, infected BGM cells were analyzed directly in aqueous medium (PBS) with a 60× water immersion objective (NA 1, Nikon).

Techniques: Infection, Imaging, Isolation, Bacteria, Comparison