Fig. 2.

Freeze-cracked nematode bodies yield stronger signals. a Scanning electron microscopy images of simple frozen and freeze-cracked C. elegans. Scale bars: 200 μm in low magnification (top), 25 μm in high magnification (bottom). b, c Averaged mass spectra ranging from m/z 700 to 1000 that were detected in the whole body of b simple frozen and c freeze-cracked C. elegans. Four of the major mass peaks at m/z 796.5, 806.5, 846.6, and 868.5 were selected to depict the thermal color scale images. d Optical images and thermal color scale images of the four selected molecules on the nematode bodies. Scale bar: 200 μm. Color scale: deep blue, faint signal; red-purple, maximum signal. e Quantitative signal intensities on nematode bodies. The data are shown as plots for each nematode (diamonds; n = 6) and mean (red line) ± SD (blue lines). The p values were calculated using a t test