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Laser-stimulated fluorescence in paleontology.

Kaye TG, Falk AR, Pittman M, Sereno PC, Martin LD, Burnham DA, Gong E, Xu X, Wang Y - PLoS ONE (2015)

Bottom Line: A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce.The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers.This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

View Article: PubMed Central - PubMed

Affiliation: Burke Museum of Natural History and Culture, Seattle, Washington, United States of America.

ABSTRACT
Fluorescence using ultraviolet (UV) light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF) is a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV. A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce. Presented here are five paleontological case histories that illustrate the technique across a broad range of specimens and scales. Novel uses such as back-lighting opaque specimens to reveal detail and detection of specimens completely obscured by matrix are highlighted in these examples. The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers. This technology has the potential to automate multiple aspects of paleontology, including preparation and sorting of microfossils. This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

No MeSH data available.


Sub-surface imaging.A, White light micrograph shows the bone fragment on the right entombed within matrix. B, Specimen under laser fluorescence. Photograph shows a high level of detail invisible under white light. Note that another much larger fragment also becomes visible (arrow). Scale bar 0.5 mm.
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pone.0125923.g008: Sub-surface imaging.A, White light micrograph shows the bone fragment on the right entombed within matrix. B, Specimen under laser fluorescence. Photograph shows a high level of detail invisible under white light. Note that another much larger fragment also becomes visible (arrow). Scale bar 0.5 mm.

Mentions: The laser has a unique ability not seen using lower intensity UV fluorescent bulbs, which is to penetrate a short distance into the matrix and fluoresce buried specimens (Fig 8A and 8B). The top image shows a partially buried bone fragment on the right in white light. Fig 8B shows the margins of the fragment in stark detail. The ability of the intense laser to penetrate into the matrix to reveal hidden specimens is a technique previously only available through regular X-rays and expensive computer tomography (CT) scans [22]. However, this laser property has already been utilized via laser-Raman and CLSM methods to characterize microscopic specimens buried within matrix [18, 19, 23]. The laser has limited penetration, but for specimens buried in finely-laminated sedimentary rocks, material may be limited to the first lamination, as was the case with this specimen. This makes the technique valuable for this and potentially many other Liaoning specimens. Specimens with a uniform matrix that is translucent to laser, fluorescent and scattered light are especially ideal for this technique. This is because the laser beam will be experience less distortion from inhomogeneities in the matrix and will achieve a greater penetration depth.


Laser-stimulated fluorescence in paleontology.

Kaye TG, Falk AR, Pittman M, Sereno PC, Martin LD, Burnham DA, Gong E, Xu X, Wang Y - PLoS ONE (2015)

Sub-surface imaging.A, White light micrograph shows the bone fragment on the right entombed within matrix. B, Specimen under laser fluorescence. Photograph shows a high level of detail invisible under white light. Note that another much larger fragment also becomes visible (arrow). Scale bar 0.5 mm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4446324&req=5

pone.0125923.g008: Sub-surface imaging.A, White light micrograph shows the bone fragment on the right entombed within matrix. B, Specimen under laser fluorescence. Photograph shows a high level of detail invisible under white light. Note that another much larger fragment also becomes visible (arrow). Scale bar 0.5 mm.
Mentions: The laser has a unique ability not seen using lower intensity UV fluorescent bulbs, which is to penetrate a short distance into the matrix and fluoresce buried specimens (Fig 8A and 8B). The top image shows a partially buried bone fragment on the right in white light. Fig 8B shows the margins of the fragment in stark detail. The ability of the intense laser to penetrate into the matrix to reveal hidden specimens is a technique previously only available through regular X-rays and expensive computer tomography (CT) scans [22]. However, this laser property has already been utilized via laser-Raman and CLSM methods to characterize microscopic specimens buried within matrix [18, 19, 23]. The laser has limited penetration, but for specimens buried in finely-laminated sedimentary rocks, material may be limited to the first lamination, as was the case with this specimen. This makes the technique valuable for this and potentially many other Liaoning specimens. Specimens with a uniform matrix that is translucent to laser, fluorescent and scattered light are especially ideal for this technique. This is because the laser beam will be experience less distortion from inhomogeneities in the matrix and will achieve a greater penetration depth.

Bottom Line: A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce.The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers.This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

View Article: PubMed Central - PubMed

Affiliation: Burke Museum of Natural History and Culture, Seattle, Washington, United States of America.

ABSTRACT
Fluorescence using ultraviolet (UV) light has seen increased use as a tool in paleontology over the last decade. Laser-stimulated fluorescence (LSF) is a next generation technique that is emerging as a way to fluoresce paleontological specimens that remain dark under typical UV. A laser's ability to concentrate very high flux rates both at the macroscopic and microscopic levels results in specimens fluorescing in ways a standard UV bulb cannot induce. Presented here are five paleontological case histories that illustrate the technique across a broad range of specimens and scales. Novel uses such as back-lighting opaque specimens to reveal detail and detection of specimens completely obscured by matrix are highlighted in these examples. The recent cost reductions in medium-power short wavelength lasers and use of standard photographic filters has now made this technique widely accessible to researchers. This technology has the potential to automate multiple aspects of paleontology, including preparation and sorting of microfossils. This represents a highly cost-effective way to address paleontology's preparatory bottleneck.

No MeSH data available.