Dichroic filter high NA objective

Ar+-laser sample scanning stage b)

FIGURE 13.8 Schematic illustration of confocal microscope used for the micro-Raman experiments. (A) The 488-nm line of an Ar+ laser is focused onto the sample with a high numerical aperture (NA) objective. The sample is mounted on an xy-piezo stage and raster-scanned over the focused laser beam. Raman scatter is collected with the same high-NA objective and focused onto a confocal aperture. The Rayleigh scatter is removed with a holographic notch filter, and the remaining Raman scatter is focused onto an avalanche photo-diode, the signal which is used to build up the image. Once a feature of interest is located, the laser beam is centered on the object and the Raman scatter is sent into a spectrometer with a back-thinned CCD camera to acquire the Raman spectra. (B) Confocal image of individual bacterial spores dried onto a calcium fluoride substrate. The bright spots correspond to the intrinsic autofluorescence and Raman scatter from the spores. Once the autofluorescence is photobleached, the Raman spectrum from the individual spore is collected.

FIGURE 13.11 BAMS at work: Three samples of particles analyzed by our real-time spectrum identification software. (a) Only the background materials have been added. (b) In addition to the background materials, Bacillus spores have been added. (c) In addition to the background materials and Bacillus spores, Clostridium spores have been added.

FIGURE 13.11 BAMS at work: Three samples of particles analyzed by our real-time spectrum identification software. (a) Only the background materials have been added. (b) In addition to the background materials, Bacillus spores have been added. (c) In addition to the background materials and Bacillus spores, Clostridium spores have been added.

Approximate Distance from Well (cm)

FIGURE 13.14 Location of ferritin in an electrophoretic gel. The figure is oriented such that the gel's well is on the left. The top portion of the figure shows the location of several elements in the gel as identified by PIXE analysis. The bottom graph indicates the co-location of proteins and iron in the gel. Iron (red line) was measured by PIXE simultaneously with STIM measurements of protein mass (blue line). Ferritin, an iron-binding protein, is shown at ~0.8 cm from the well, the overlap of the protein and iron curves.

Approximate Distance from Well (cm)

FIGURE 13.14 Location of ferritin in an electrophoretic gel. The figure is oriented such that the gel's well is on the left. The top portion of the figure shows the location of several elements in the gel as identified by PIXE analysis. The bottom graph indicates the co-location of proteins and iron in the gel. Iron (red line) was measured by PIXE simultaneously with STIM measurements of protein mass (blue line). Ferritin, an iron-binding protein, is shown at ~0.8 cm from the well, the overlap of the protein and iron curves.

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