Name: use of autometallography to localize and semi-quantify silver in cetacean tissues
Uploaded: 2018-10-04T13:30:00
Description: Watch this Scientific Journal Video about Use of Autometallography to Localize and Semi-Quantify Silver in Cetacean Tissues at JoVE.com

We thank the Taiwan Cetacean Stranding Network for sample collection and storage, including the Taiwan Cetacean Society, Taipei; the Cetacean Research Laboratory (Prof. Lien-Siang Chou), the Institute of Ecology and Evolutionary Biology, National Taiwan University, Taipei; the National Museum of Natural Science (Dr. Chiou-Ju Yao), Taichung; and the Marine Biology &#38; Cetacean Research Center, National Cheng-Kung University. We also thank the Forestry Bureau, Council of Agriculture, Executive Yuan for their permit.

The study was performed in accordance with international guidelines, and the use of cetacean tissue samples was permitted by the Council of Agriculture of Taiwan (Research Permit 104-07.1-SB-62).
1. Tissue Sample Preparation for ICP-MS Analysis
Note: The liver and kidney tissues were collected from freshly dead and moderately autolyzed stranded cetaceans24, including 6 stranded cetaceans of 4 different species, 1 Grampus griseus (Gg), ...

<ol>
	<li>McGillicuddy, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silver+nanoparticles+in+the+environment:+Sources,+detection+and+ecotoxicology.">Silver nanoparticles in the environment: Sources, detection and ecotoxicology.</a> Science Total Environment. 575, 231-246 (2017).</li><li>Yu, S. J., Yin, Y. G., Liu, J. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Silver+nanoparticles+in+the+environment.">Silver nanoparticles in the environment.</a> Environmental Science: Processes and Impacts. 15 (1), 78-92 (2013).</li><li>Hansen, S. F., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoproducts-+what+is+actually+available+to+European+consumers?.">Nanoproducts- what is actually available to European consumers?.</a> Environmental Science: Nano. 3 (1), 169-180 (2016).</li><li>Vance, M. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanotechnology+in+the+real+world:+Redeveloping+the+nanomaterial+consumer+products+inventory.">Nanotechnology in the real world: Redeveloping the nanomaterial consumer products inventory.</a> Beilstein Journal of Nanotechnology. 6, 1769-1780 (2015).</li><li>Farre, M., Gajda-Schrantz, K., Kantiani, L., Barcelo, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ecotoxicity+and+analysis+of+nanomaterials+in+the+aquatic+environment.">Ecotoxicity and analysis of nanomaterials in the aquatic environment.</a> Analytical and Bioanalytical Chemistry. 393 (1), 81-95 (2009).</li><li>Walters, C. R., Pool, E. J., Somerset, V. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ecotoxicity+of+silver+nanomaterials+in+the+aquatic+environment:+a+review+of+literature+and+gaps+in+nano-toxicological+research.">Ecotoxicity of silver nanomaterials in the aquatic environment: a review of literature and gaps in nano-toxicological research.</a> Journal of Environmental Science and Health. Part A, Toxic/hazardous Substances &amp; Environmental Engineering. 49 (13), 1588-1601 (2014).</li><li>Levard, C., Hotze, E. M., Lowry, G. V., Brown, G. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Environmental+transformations+of+silver+nanoparticles:+impact+on+stability+and+toxicity.">Environmental transformations of silver nanoparticles: impact on stability and toxicity.</a> Environmental Science &amp; Technology. 46 (13), 6900-6914 (2012).</li><li>Massarsky, A., Trudeau, V. L., Moon, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predicting+the+environmental+impact+of+nanosilver.">Predicting the environmental impact of nanosilver.</a> Environmental Toxicology and Pharmacology. 38 (3), 861-873 (2014).</li><li>Wang, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toxicity,+bioaccumulation,+and+biotransformation+of+silver+nanoparticles+in+marine+organisms.">Toxicity, bioaccumulation, and biotransformation of silver nanoparticles in marine organisms.</a> Environmental Science and Technology. 48 (23), 13711-13717 (2014).</li><li>Buffet, P. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+marine+mesocosm+study+on+the+environmental+fate+of+silver+nanoparticles+and+toxicity+effects+on+two+endobenthic+species:+the+ragworm+Hediste+diversicolor+and+the+bivalve+mollusc+Scrobicularia+plana.">A marine mesocosm study on the environmental fate of silver nanoparticles and toxicity effects on two endobenthic species: the ragworm Hediste diversicolor and the bivalve mollusc Scrobicularia plana.</a> Science of the Total Environment. 470, 1151-1159 (2014).</li><li>Chen, M. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Baseline+metal+concentrations+in+sediments+and+fish,+and+the+determination+of+bioindicators+in+the+subtropical+Chi-ku+Lagoon,+S+W+Taiwan.">Baseline metal concentrations in sediments and fish, and the determination of bioindicators in the subtropical Chi-ku Lagoon, S W Taiwan.</a> Marine Pollution Bulletin. 44 (7), 703-714 (2002).</li><li>Li, W. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+of+silver+(Ag)+deposition+in+tissues+from+stranded+cetaceans+by+autometallography+(AMG).">Investigation of silver (Ag) deposition in tissues from stranded cetaceans by autometallography (AMG).</a> Environmental Pollution. , 534-545 (2018).</li><li>Chen, M. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+concentrations+of+four+Taiwanese+toothed+cetaceans+indicating+the+silver+and+cadmium+pollution+in+the+western+Pacific+Ocean.">Tissue concentrations of four Taiwanese toothed cetaceans indicating the silver and cadmium pollution in the western Pacific Ocean.</a> Marine Pollution Bulletin. 124 (2), 993-1000 (2017).</li><li>Li, W. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunotoxicity+of+silver+nanoparticles+(AgNPs)+on+the+leukocytes+of+common+bottlenose+dolphins+(Tursiops+truncatus).">Immunotoxicity of silver nanoparticles (AgNPs) on the leukocytes of common bottlenose dolphins (Tursiops truncatus).</a> Scientific Reports. , (2018).</li><li>Bornhorst, J. A., Hunt, J. W., Urry, F. M., McMillin, G. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+sample+preservation+methods+for+clinical+trace+element+analysis+by+inductively+coupled+plasma+mass+spectrometry.">Comparison of sample preservation methods for clinical trace element analysis by inductively coupled plasma mass spectrometry.</a> American Journal of Clinical Pathology. 123 (4), 578-583 (2005).</li><li>Bonta, M., Torok, S., Hegedus, B., Dome, B., Limbeck, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparison+of+sample+preparation+strategies+for+biological+tissues+and+subsequent+trace+element+analysis+using+LA-ICP-MS.">A comparison of sample preparation strategies for biological tissues and subsequent trace element analysis using LA-ICP-MS.</a> Analytical and Bioanalytical Chemistry. 409 (7), 1805-1814 (2017).</li><li>Bischoff, K., Lamm, C., Erb, H. N., Hillebrandt, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effects+of+formalin+fixation+and+tissue+embedding+of+bovine+liver+on+copper,+iron,+and+zinc+analysis.">The effects of formalin fixation and tissue embedding of bovine liver on copper, iron, and zinc analysis.</a> Journal of Veterinary Diagnostic Investigation. 20 (2), 220-224 (2008).</li><li>Miller, D. L., Yu, I. J., Genter, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+Autometallography+in+Studies+of+Nanosilver+Distribution+and+Toxicity.">Use of Autometallography in Studies of Nanosilver Distribution and Toxicity.</a> International Journal of Toxicology. 35 (1), 47-51 (2016).</li><li>Anderson, D. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+particle+size+on+persistence+and+clearance+of+aerosolized+silver+nanoparticles+in+the+rat+lung.">Influence of particle size on persistence and clearance of aerosolized silver nanoparticles in the rat lung.</a> Toxicological Sciences. 144 (2), 366-381 (2015).</li><li>Kim, W. Y., Kim, J., Park, J. D., Ryu, H. Y., Yu, I. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histological+study+of+gender+differences+in+accumulation+of+silver+nanoparticles+in+kidneys+of+Fischer+344+rats.">Histological study of gender differences in accumulation of silver nanoparticles in kidneys of Fischer 344 rats.</a> Journal of Toxicology and Environmental Health, Part A. 72 (21-22), 1279-1284 (2009).</li><li>Danscher, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+autometallography+to+heavy+metal+toxicology.">Applications of autometallography to heavy metal toxicology.</a> Pharmacology Toxicology. 68 (6), 414-423 (1991).</li><li>Deroulers, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analyzing+huge+pathology+images+with+open+source+software.">Analyzing huge pathology images with open source software.</a> Diagnostic Pathology. 8, 92 (2013).</li><li>Shu, J., Dolman, G. E., Duan, J., Qiu, G., Ilyas, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Statistical+colour+models:+an+automated+digital+image+analysis+method+for+quantification+of+histological+biomarkers.">Statistical colour models: an automated digital image analysis method for quantification of histological biomarkers.</a> BioMedical Engineering Online. 15, 46 (2016).</li><li>Geraci, J. R., Lounsbury, V. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specimen+and+data+collection.">Specimen and data collection.</a> Marine mammals ashore: a field guide for strandings. , 167-230 (2005).</li><li>Shih, C. -. C., Liu, L. -. L., Chen, M. -. H., Wang, W. -. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Investigation of heavy metal bioaccumulation in dolphins from the coastal waters off Taiwan. , (2001).</li><li>Liang, C. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relationship+between+the+striatal+dopamine+transporter+and+novelty+seeking+and+cognitive+flexibility+in+opioid+dependence.">The relationship between the striatal dopamine transporter and novelty seeking and cognitive flexibility in opioid dependence.</a> Progress in Neuro-Psychopharmacology and Biological Psychiatry. 74, 36-42 (2017).</li><li>Spiess, A. N., Neumeyer, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+evaluation+of+R2+as+an+inadequate+measure+for+nonlinear+models+in+pharmacological+and+biochemical+research:+a+Monte+Carlo+approach.">An evaluation of R2 as an inadequate measure for nonlinear models in pharmacological and biochemical research: a Monte Carlo approach.</a> BMC Pharmacology. 10, 6 (2010).</li><li>Stoltenberg, M., Danscher, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histochemical+differentiation+of+autometallographically+traceable+metals+(Au,+Ag,+Hg,+Bi,+Zn):+protocols+for+chemical+removal+of+separate+autometallographic+metal+clusters+in+Epon+sections.">Histochemical differentiation of autometallographically traceable metals (Au, Ag, Hg, Bi, Zn): protocols for chemical removal of separate autometallographic metal clusters in Epon sections.</a> Histochemical Journal. 32 (11), 645-652 (2000).</li><li>Dimitriadis, V. K., Domouhtsidou, G. P., Raftopoulou, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Localization+of+Hg+and+Pb+in+the+palps,+the+digestive+gland+and+the+gills+in+Mytilus+galloprovincialis+(L.)+using+autometallography+and+X-ray+microanalysis.">Localization of Hg and Pb in the palps, the digestive gland and the gills in Mytilus galloprovincialis (L.) using autometallography and X-ray microanalysis.</a> Environmental Pollution. 125 (3), 345-353 (2003).</li><li>Loumbourdis, N. S., Danscher, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autometallographic+tracing+of+mercury+in+frog+liver.">Autometallographic tracing of mercury in frog liver.</a> Environmental Pollution. 129 (2), 299-304 (2004).</li><li>Stoltenberg, M., Larsen, A., Kemp, K., Bloch, D., Weihe, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autometallographic+tracing+of+mercury+in+pilot+whale+tissues+in+the+Faroe+Islands.">Autometallographic tracing of mercury in pilot whale tissues in the Faroe Islands.</a> International Journal of Circumpolar Health. 62 (2), 182-189 (2003).</li></ol>

The purpose of the article study is to establish an adjuvant method to evaluate the Ag distribution at suborgan levels and to estimate Ag concentrations in cetacean tissues. The current protocols include 1) Determination of Ag concentrations in cetacean tissues by ICP-MS, 2) AMG analysis of pair-matched tissue samples with known Ag concentrations, 3) Establishment of the regression model (CHAA) for estimating the Ag concentrations by AMG positive values, 4) Evaluation of the accuracy and precision of CHAA, and 5) Estimat...

Silver nanoparticles (AgNPs) have been extensively used in commercial products, including textiles, cosmetics, and health care items, due to their great antimicrobial effects1,2. Therefore, the production of AgNPs and the number of AgNP-containing products are increased over time3,4. However, AgNPs may be released into the environment and accumulate in the ocean5,6. They have become the major source of Ag contamination, and the public awareness of the environmental toxicity of Ag is increasing.
The status of AgNPs and Ag in the marine environment is complicated and constantly changing. Previous studies have indicated that AgNPs can remain as particles, aggregate, dissolve, react with different chemical species, or be regenerated from Ag+ ions7,8. Several types of Ag compounds, such as AgCl, have been found in marine sediments, where they can be ingested by benthic organisms and enter the food chain9,10. According to a previous study conducted in the Chi-ku Lagoon area along the southwestern coast of Taiwan, the Ag concentrations of marine sediments are extremely low and similar to the crustal abundance, and those of fish liver tissue are usually below the detection limit (&#60; 0.025 &#956;g/g wet/wet)11. However, previous studies conducted in different countries have demonstrated relatively high Ag concentrations in the livers of cetaceans12,13. The Ag concentration in the livers of cetaceans is age-dependent, suggesting that the source of Ag in their bodies is most likely their prey12. These findings further suggest the biomagnification of Ag in animals at higher trophic levels. Cetaceans, as the apex predators in the ocean, may have suffered negative health impacts caused by Ag/Ag compounds12,13,14. Most importantly, like cetaceans, humans are mammals, and the negative health impacts caused by Ag/Ag compounds in cetaceans may also occur in humans. In other words, cetaceans could be sentinel animals for the health of marine environment and humans. Therefore, the health effects, the tissue distribution, and concentration of Ag in cetaceans are of great concern.
Although the concentrations of Ag/Ag compounds in cetacean tissues can be measured by inductively coupled plasma mass spectroscopy (ICP-MS), the use of ICP-MS is limited by its high capital cost (instrument and maintenance) and the requirements for tissue storage/preparation12,15. In addition, it is usually difficult to collect comprehensive tissue samples in all investigations of stranded cetacean cases due to logistical difficulties, a shortage of manpower, and a lack of related resources12. The frozen tissue samples for ICP-MS analysis are not easily stored because of limited refrigeration space, and frozen tissue samples may be discarded due to broken refrigeration equipment12. These aforementioned obstacles hamper investigations of contamination levels in cetacean tissues by ICP-MS analysis using frozen tissue samples. In contrast, formalin fixed tissue samples are relatively easy to collect during the necropsy of dead-stranded cetaceans. Therefore, it is necessary to develop an easy to use and inexpensive method to detect/measure the heavy metals in cetacean tissues by using formalin fixed tissue samples.
Although the suborgan distributions and concentrations of alkali and alkaline earth metals may be altered during the formalin-fixed, paraffin-embedded (FFPE) process, only lesser effects on transition metals, such as Ag, have been noted16. Hence, FFPE tissue has been considered as an ideal sample resource for metal localization and measurements16,17. Autometallography (AMG), a histochemical process, can amplify heavy metals as variably sized golden yellow to black AMG positive signals on FFPE tissue sections, and these amplified heavy metals can be visualized under light microscopy18,19,20,21. Hence, the AMG method provides information on the suborgan distributions of heavy metals. It can provide important additional information for studying the metabolic pathways of heavy metals in biological systems because ICP-MS can only measure the concentration of heavy metals at the organ level18. Furthermore, digital image analysis software, such as ImageJ, has been applied to the quantitative analysis of histological tissue sections22,23. The variably-sized golden yellow to black AMG positive signals of FFPE tissue sections can be quantified and used to estimate the concentrations of heavy metals. Although the absolute Ag concentration cannot be directly determined by the AMG method with image quantitative analysis, it can be estimated by a regression model based on the data obtained from the image quantitative analysis and ICP-MS, which is named cetacean histological Ag assay (CHAA). Considering the difficulties in measuring Ag concentrations by ICP-MS analysis in most stranded cetaceans, CHAA is a valuable adjuvant method to estimate Ag concentrations in cetacean tissues, which cannot be determined by ICP-MS analysis due to the lack of frozen tissue samples. This paper describes the protocol of a histochemical technique (AMG method) for localizing Ag at the suborgan level and an assay named CHAA to estimate the Ag concentrations in the liver and kidney tissues of cetaceans.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/58232/58232fig1.jpg" /> 
Figure 1: Flowchart depicting the establishment and application of cetacean histological Ag assay (CHAA) for estimating Ag concentrations. CHAA = cetacean histological Ag assay, FFPE = Formalin-fixed, paraffin-embedded, ICP-MS = inductively coupled plasma mass spectroscopy. <a href="https://www.jove.com/files/ftp_upload/58232/58232fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

<table>
	<tbody>
		<tr>
			<td>HQ Silver enhancement kit</td>
			<td>Nanoprobes</td>
			<td>#2012</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgipath Paraplast</td>
			<td>Leica Biosystems</td>
			<td>39601006</td>
			<td>Paraffin</td>
		</tr>
		<tr>
			<td>100% Ethanol</td>
			<td>Muto Pure Chemical Co., Ltd</td>
			<td>4026</td>
			<td></td>
		</tr>
		<tr>
			<td>Non-Xylene</td>
			<td>Muto Pure Chemical Co., Ltd</td>
			<td>4328</td>
			<td></td>
		</tr>
		<tr>
			<td>Silane coated slide</td>
			<td>Muto Pure Chemical Co., Ltd</td>
			<td>511614</td>
			<td></td>
		</tr>
		<tr>
			<td>Cover glass (25 x 50 mm)</td>
			<td>Muto Pure Chemical Co., Ltd</td>
			<td>24501</td>
			<td></td>
		</tr>
		<tr>
			<td>Malinol</td>
			<td>Muto Pure Chemical Co., Ltd</td>
			<td>20092</td>
			<td></td>
		</tr>
		<tr>
			<td>GM Haematoxylin Staining</td>
			<td>Muto Pure Chemical Co., Ltd</td>
			<td>3008-1</td>
			<td></td>
		</tr>
		<tr>
			<td>10% neutral buffered formalin solution</td>
			<td>Chin I Pao Co., Ltd</td>
			<td>---</td>
			<td></td>
		</tr>
		<tr>
			<td>Tip (1000 &#956;L)</td>
			<td>MDBio, Inc.</td>
			<td>1000</td>
			<td></td>
		</tr>
		<tr>
			<td>PIPETMAN Classic P1000</td>
			<td>Gilson, Inc.</td>
			<td>F123602</td>
			<td></td>
		</tr>
		<tr>
			<td>15 ml Centrifuge Tube</td>
			<td>GeneDireX, Inc.</td>
			<td>PC115-0500</td>
			<td></td>
		</tr>
		<tr>
			<td>Dogfish liver</td>
			<td>National Research Council of Canada</td>
			<td>DOLT-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Dogfish muscle</td>
			<td>National Research Council of Canada</td>
			<td>DORM-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Inductively coupled plasma mass spectrometry (ICP-MS)</td>
			<td>PerkinElmer Inc.</td>
			<td>PE-SCIEX ELAN 6100 DRC</td>
			<td></td>
		</tr>
		<tr>
			<td>FreeZone 6 liter freeze dry system</td>
			<td>Labconco</td>
			<td>7752030</td>
			<td>For freeze drying</td>
		</tr>
		<tr>
			<td>BRAND&#174; SILBERBRAND volumetric flask</td>
			<td>Merck</td>
			<td>Z326283</td>
			<td></td>
		</tr>
		<tr>
			<td>30 mL standard vial, flat interior with 33 mm closure</td>
			<td>Savillex Corporation</td>
			<td>200-030-12</td>
			<td>For diagestion</td>
		</tr>
		<tr>
			<td>Nitric acid, superpur&#174;, 65.0%</td>
			<td>Merck</td>
			<td>1.00441</td>
			<td>For diagestion</td>
		</tr>
		<tr>
			<td>Hot Plate/Stirrers</td>
			<td>Corning&#174;</td>
			<td>PC-220</td>
			<td>For diagestion</td>
		</tr>
		<tr>
			<td>High Shear lab mixer</td>
			<td>Silverson</td>
			<td>SL2T</td>
			<td>For homogenization</td>
		</tr>
		<tr>
			<td>Sterile polypropylene sample jar (250mL)</td>
			<td>Thermo Scientific&#8482;</td>
			<td>6186L05</td>
			<td>For homogenization</td>
		</tr>
		<tr>
			<td>Digital camera</td>
			<td>Nikon Corporation</td>
			<td>DS-Fi2</td>
			<td></td>
		</tr>
		<tr>
			<td>Light microscope</td>
			<td>Nikon Corporation</td>
			<td>ECLIPSE Ni-U</td>
			<td></td>
		</tr>
		<tr>
			<td>Shandon&#8482; Finesse&#8482; 325 manual microtome</td>
			<td>Thermo Scientific&#8482;</td>
			<td>A78100001H</td>
			<td></td>
		</tr>
		<tr>
			<td>Accu-Cut&#174; SRM&#8482; 200 rotary microtome</td>
			<td>Sakura</td>
			<td>1429</td>
			<td></td>
		</tr>
		<tr>
			<td>Microtome blade S35</td>
			<td>FEATHER&#174;</td>
			<td>207500000</td>
			<td></td>
		</tr>
		<tr>
			<td>Slide staining dish and cover</td>
			<td>Brain Research Laboratories</td>
			<td>#3215</td>
			<td></td>
		</tr>
		<tr>
			<td>Steel staining rack</td>
			<td>Brain Research Laboratories</td>
			<td>#3003</td>
			<td></td>
		</tr>
		<tr>
			<td>Shandon embedding center</td>
			<td>Thermo Scientific&#8482;</td>
			<td>S-EC</td>
			<td></td>
		</tr>
		<tr>
			<td>Shandon Citadel&#174; tissue processor</td>
			<td>Thermo Scientific&#8482;</td>
			<td>69800003</td>
			<td></td>
		</tr>
		<tr>
			<td>Slide warmer</td>
			<td>Lab-Line Instruments</td>
			<td>26005</td>
			<td></td>
		</tr>
		<tr>
			<td>Water bath</td>
			<td>Shandon Capshaw</td>
			<td>3964</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter paper</td>
			<td>Merck</td>
			<td>1541-070</td>
			<td></td>
		</tr>
		<tr>
			<td>Prism 6.01 for windows</td>
			<td>GraphPad Software</td>
			<td></td>
			<td>Statistic software</td>
		</tr>
		<tr>
			<td>ImageJ</td>
			<td>National Institutes of Health</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Stainless steel tissue embedding mould</td>
			<td>Shenyang Roundfin Trade Co., Ltd</td>
			<td>RD-TBM003</td>
			<td>For paraffin emedding</td>
		</tr>
	</tbody>
</table>

use of autometallography to localize and semi-quantify silver in cetacean tissues

Silver nanoparticles (AgNPs) have been extensively used in commercial products, including textiles, cosmetics, and health care items, due to their strong antimicrobial effects. They also may be released into the environment and accumulate in the ocean. Therefore, AgNPs are the major source of Ag contamination, and public awareness of the environmental toxicity of Ag is increasing. Previous studies have demonstrated the bioaccumulation (in producers) and magnification (in consumers/predators) of Ag. Cetaceans, as the apex predators of ocean, may have been negatively affected by the Ag/Ag compounds. Although the concentrations of Ag/Ag compounds in cetacean tissues can be measured by inductively coupled plasma mass spectroscopy (ICP-MS), the use of ICP-MS is limited by its high capital cost and the requirement for tissue storage/preparation. Therefore, an autometallography (AMG) method with an image quantitative analysis by using formalin-fixed, paraffin-embedded (FFPE) tissue may be an adjuvant method to localize Ag distribution at the suborgan level and estimate the Ag concentration in cetacean tissues. The AMG positive signals are mainly brown to black granules of various sizes in the cytoplasm of proximal renal tubular epithelium, hepatocytes, and Kupffer cells. Occasionally, some amorphous golden yellow to brown AMG positive signals are noted in the lumen and basement membrane of some proximal renal tubules. The assay for estimating the Ag concentration is named the Cetacean Histological Ag Assay (CHAA), which is a regression model established by the data from image quantitative analysis of the AMG method and ICP-MS. The use of AMG with CHAA to localize and semi-quantify heavy metals provides a convenient methodology for spatio-temporal and cross-species studies.

Representative images of the AMG positive signals in the cetacean liver and kidney tissues are shown in Figure 5. The AMG positive signals include variably-sized brown to black granules of various sizes in the cytoplasm of proximal renal tubular epithelium, hepatocytes, and Kupffer cells. Occasionally, amorphous golden yellow to brown AMG positive signals are noted in the lumen and basement membrane of some proximal renal tubules. There is a positive correlat...

Watch this Scientific Journal Video about Use of Autometallography to Localize and Semi-Quantify Silver in Cetacean Tissues at JoVE.com

Use of Autometallography to Localize and Semi-Quantify Silver in Cetacean Tissues

A protocol is presented to localize Ag in cetacean liver and kidney tissues by autometallography. Furthermore, a new assay, named the cetacean histological Ag assay (CHAA) is developed to estimate the Ag concentrations in those tissues.

Silver nanoparticles (AgNPs) have been extensively used in commercial products, including textiles, cosmetics, and health care items, due to their strong ...

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