The authors acknowledge the contribution of Hammond Bay Biological Station, Great Lakes Science Center, U.S. Geological Survey. We also thank Dr. Melinda Frame at the Center for Advanced Microscopy at Michigan State University for her technical support in laser scanning confocal microscopy. This study is supported by grants from the Great Lakes Fishery Commission to YWCD and WML.

1. Solution Preparation
<ol>
	<li>Make 1 L 10x 0.1 M phosphate buffer saline (PBS, pH 7.4): Weigh 26.2 g sodium phosphate (monobasic), 115 g sodium phosphate (dibasic), and 87.66 g NaCl. Dissolve in about 800 ml distilled H2O, adjust pH, and bring the volume up to 1 L with distilled H2O.
	<ol>
		<li>Make 1 L 0.1 M phosphate buffer saline (pH 7.4): Take 100 ml 10x PBS, and add 900 ml distilled H2O.</li>
		<li>Make 1 L 0.1 M phosphate buffer saline (pH 7.4) with 0.1% Triton X-100: Take 100 ml 10x PBS, add 1 ml Triton X-100, and bring the volume up to 1 L with distilled H2O.</li>
	</ol>
	</li>
	<li>Make 1 L 10x 0.1M phosphate buffer (PB, pH 7.4): Weigh 26.2 g sodium phosphate (monobasic) and 115 g sodium phosphate (dibasic). Dissolve in about 800 ml distilled H2O, adjust pH, and bring the volume up to 1 L with distilled H2O.
	<ol>
		<li>Make 1 L 0.1 M phosphate buffer (pH 7.4): Take 100 ml 10x PB, and add 900 ml distilled H2O.</li>
		<li>Make 1 L 0.1 M phosphate buffer (pH 7.4) with 0.1% Triton X-100: Take 100 ml 10x PB, add 1 ml Triton X-100, and bring the volume up to 1 L with distilled H2O.</li>
	</ol>
	</li>
	<li>Make 400 ml hydrogel monomer solution (4% acrylamide, 0.25% bis-acrylamide, 4% paraformaldehyde, 0.0075% ammonium persulfate, 0.0005% saponin in 0.1 M PBS): Weigh 0.3 g ammonium persulfate and 0.2 g saponin. Add 210 ml distilled H2O, 40 ml 40% acrylamide, 10 ml 2% bis-acrylamide, 40 ml 10x PBS (pH 7.4), 100 ml 16% paraformaldehyde, and mix well.</li>
	<li>Make 4 L clearing solution (4% SDS in 0.2 M boric acid): Weigh 49.464 g boric acid and 160 g SDS. Dissolve in about 3.5 L distilled H2O, adjust pH to 8.5 with NaOH, and bring the volume up to 4 L.</li>
	<li>Make 1 L 80% glycerol solution: Measure 800 ml glycerol, add 200 ml distilled H2O, and mix well.</li>
</ol>
2. Tissue Preparation
<ol>
	<li>Prepare hydrogel monomer solution and aliquot 10 ml to each 15 ml centrifuge tube.</li>
	<li>Dissect the whole tissue and fix in the hydrogel for 2 days at 4 &#176;C. Make sure that the hydrogel solution is at least 10x the volume of the tissue.</li>
	<li>Bring the hydrogel fixed tissue (in the 15 ml centrifuge tube) to a fume hood.</li>
	<li>Polymerize the hydrogel fixed tissue by adding 5 &#181;l TEMED, mix well, and let sit in the fume hood at room temperature for 2-3 hr.</li>
	<li>Remove the excess gel thoroughly. Note: Extra gel will hinder the clearing process and the antibody penetration during staining.</li>
	<li>Incubate the fixed tissue in 10 ml clearing solution in an incubator shaker set at 70 rpm and 50 &#176;C for several days until the tissue becomes transparent. Change clearing solution at least once per day and remove the excess gel from the tissue when changing the clearing solution.</li>
	<li>Rinse the tissue in 10 ml 0.1 M PB with 0.1% Triton X-100 at 70 rpm and 37 &#176;C overnight. Repeat this step 3 times and remove the excess gel from the tissue when changing the buffer solution.</li>
	<li>Incubate the clarified tissue in the primary antibody solution in PB with 0.1% Triton X-100 at 70 rpm and 37 &#176;C for 2 days. Note: Make enough primary antibody solution to submerge the whole tissue.</li>
	<li>Rinse the tissue in 10 ml PB with 0.1% Triton X-100 at 70 rpm and 37 &#176;C overnight. Repeat this step 3 times and remove the excess gel from the tissue when changing the buffer solution.</li>
	<li>Perform the following steps in a dark room or under dim light. Cover the samples with foil to prevent photo bleaching.</li>
	<li>Incubate the clarified tissue with the fluorescent secondary antibody solution in PB with 0.1% Triton X-100 and the blocking serum at 70 rpm and 37 &#176;C for 1 day.</li>
	<li>Rinse the tissue in 10 ml PB with 0.1% Triton X-100 at 70 rpm and 37 &#176;C overnight. Repeat this step 3 times and remove the excess gel from the tissue when changing the buffer solution.</li>
	<li>Rinse the tissue in 10 ml PBS at 70 rpm and 37 &#176;C overnight. Repeat this step 3 times and remove the excess gel from the tissue when changing the buffer solution.</li>
	<li>Incubate the clarified tissue in 80% glycerol at 70 rpm and 37 &#176;C overnight.</li>
	<li>Store the fluorescent stained tissue at 4 &#176;C prior to confocal microscopy.</li>
</ol>

<ol>
	<li>Applegate, V. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Natural+history+of+the+sea+lamprey+(Petromyzon+marinus)+in+Michigan.">Natural history of the sea lamprey (Petromyzon marinus) in Michigan.</a> US Fish and Wildlife Service Special Science Report on Fishery Service. (55), (1950).</li><li>Hardisty, M. W., Potter, I. C., Hardisty, M. W., Potter, I. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+general+biology+of+adult+lampreys.">The general biology of adult lampreys.</a> The biology of lampreys. 1, 127-206 (1971).</li><li>Youson, J. H., Potter, I. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+description+of+the+stages+in+the+metamorphosis+of+the+anadromous+sea+lamprey,+Petromyzon+marinus+L.">A description of the stages in the metamorphosis of the anadromous sea lamprey, Petromyzon marinus L.</a> Can. J. Zool. 57, 1808-1817 (1979).</li><li>Boomer, L. A., 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=Cholangiocyte+apoptosis+is+an+early+event+during+induced+metamorphosis+in+the+sea+lamprey,+Petromyzon+marinus+L.">Cholangiocyte apoptosis is an early event during induced metamorphosis in the sea lamprey, Petromyzon marinus L.</a> J. Pediatr. Surg. 45, 114-120 (2010).</li><li>Kasai, M., Suzuki, H., Ohashi, E., Ohi, R., Chiba, T., Okamoto, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Technique+and+results+of+operative+management+of+biliary+atresia.">Technique and results of operative management of biliary atresia.</a> World J. Surg. 2, 571-580 (1978).</li><li>Suzuki, T., Hashimoto, T., Kondo, S., Sato, Y., Hussein, 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=Evaluating+patients&#8217;+outcome+post-Kasai+operation:+a+19-year+experience+with+modification+of+the+hepatic+portoenterostomy+and+applying+a+novel+steroid+therapy+regimen.">Evaluating patients&#8217; outcome post-Kasai operation: a 19-year experience with modification of the hepatic portoenterostomy and applying a novel steroid therapy regimen.</a> Pediatr. Surg. Int. 26, 825-830 (2010).</li><li>Hartley, J. L., Davenport, M., Kelly, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biliary+atresia.">Biliary atresia.</a> Lancet. 374, 1704-1713 (2009).</li><li>Morecki, R., Glaser, J. H., Cho, S., Balistreri, W. F., Horwitz, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biliary+atresia+and+reovirus+type+3+infection.">Biliary atresia and reovirus type 3 infection.</a> New Engl. J. Med. 307, 481-484 (1982).</li><li>Shimadera, S., Iwai, N., Deguchi, E., Kimura, O., Fumino, S., Yokoyama, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+inv+mouse+as+an+experimental+model+of+biliary+atresia.">The inv mouse as an experimental model of biliary atresia.</a> J. Pediatr. Surg. 42, 1555-1560 (2007).</li><li>Sidon, E. W., Youson, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphological+changes+in+the+liver+of+the+sea+lamprey,+Petromyzon+marinus+L.,+during+metamorphosis:+I.+Atresia+of+the+bile+ducts.">Morphological changes in the liver of the sea lamprey, Petromyzon marinus L., during metamorphosis: I. Atresia of the bile ducts.</a> J. Morphol. 177, 109-124 (1983).</li><li>Yeh, C. -. Y., Chung-Davidson, Y. -. W., Wang, H., Li, K., Li, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intestinal+synthesis+and+secretion+of+bile+salts+as+an+adaptation+to+developmental+biliary+atresia+in+the+sea+lamprey.">Intestinal synthesis and secretion of bile salts as an adaptation to developmental biliary atresia in the sea lamprey.</a> Proc. Nat. Acad. Sci. U.S.A. 109, 11419-11424 (2012).</li><li>Chung, K., 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=Structural+and+molecular+interrogation+of+intact+biological+systems.">Structural and molecular interrogation of intact biological systems.</a> Nature. 497, 332-337 (2013).</li><li>Alarc&#243;n, V. B., Filosa, M. F., Youson, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytokeratins+in+the+liver+of+the+sea+lamprey+(Petromyzon+marinus)+before+and+after+metamorphosis.">Cytokeratins in the liver of the sea lamprey (Petromyzon marinus) before and after metamorphosis.</a> Cell Tissue Res. 287, 365-374 (1997).</li><li>Youson, J. H., Ogilvie, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrastructural+features+of+degeneration+of+the+gallbladder+during+lamprey+biliary+atresia.">Ultrastructural features of degeneration of the gallbladder during lamprey biliary atresia.</a> Tissue and Cell. 22, 477-492 (1990).</li><li>Morii, M., 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=Onset+of+apoptosis+in+the+cystic+duct+during+metamorphosis+of+a+Japanese+lamprey,+Lethenteron+reissneri.">Onset of apoptosis in the cystic duct during metamorphosis of a Japanese lamprey, Lethenteron reissneri.</a> Anat. Rec. 293, 1155-1166 (2010).</li></ol>

The authors have nothing to disclose.

This protocol is modified from a new method called &#8220;CLARITY&#8221;12, which crosslinks intact tissue with polyacrylamide to form a nanoporous hydrogel, and then strips away the plasma membrane of the tissue to achieve optical transparency and macromolecular permeability. &#8220;CLARITY&#8221; allows intact-tissue imaging of long-range projection and local circuit wiring in the nervous system. This new method can be used to visualize the entire biliary system in sea lamprey liver during metamorphosis. It ...

Sea lamprey develop through three distinct life stages1,2. Larval sea lamprey (L) spend most time in burrows as benthic filter feeders. After going through seven metamorphic stages of dramatic changes in external morphology and reorganization in internal organs3, the resulting juveniles (JV) enter a parasitic stage during which they feed on blood and tissue fluids from host fish, increasing the body mass more than 100 times. After 1.0 to 1.5 years feeding on the host fish in the ocean or large lakes, adults cease feeding during the early spring and migrate into rivers to spawn and then die1,2.

During metamorphosis, the sea lamprey liver loses the gall bladder and the entire biliary tree, an evolutionary mutant phenotype that mimics the human infant disease biliary atresia. Infant biliary atresia is a rare pediatric liver disease with severe medical complications4,5,6,7,8,9,10, however the pathogenesis and etiology of biliary atresia are largely unknown4. Patients with biliary atresia die within two years after birth unless surgical intervention (Kasai procedure) is performed5. Subsequently, these patients require extensive clinical management and often liver transplantation&#160;6. Many theories of biliary atresia etiopathogenesis have been proposed, such as viral infection, congenital malformation, autoimmune disease, and toxic insult. However, the contribution of each to the development of biliary atresia remains inconclusive7,8,9,10.

Unlike infants that suffer pathological biliary atresia, sea lamprey undergo developmentally programmed biliary atresia without extensive necroinflammation, fibrosis or cirrhosis10. The animals may suffer transient cholestasis during this process10, but adapt to this developmental condition via de novo synthesis and secretion of bile salts in the intestine after developmental biliary atresia, in addition to known mechanisms such as reduction of bile salt synthesis in liver11. This developmental process in sea lamprey provides the only known opportunity to examine the progression of biliary atresia.

A newly-developed method called &#8220;CLARITY&#8221; enables high-resolution imaging in complex mammalian nervous systems by transforming intact tissue into an optically transparent nanoporous hydrogel12. Using sea lamprey liver and a modified CLARITY protocol, intact-tissue imaging of biliary degeneration can be documented throughout liver metamorphosis.

<table border="0" cellpadding="0" cellspacing="0" width="702">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">40% acrylamide&#160;</td>
			<td style="width:200px;">Bio-Rad</td>
			<td style="width:119px;">161-0140</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">2% bis-acrylamide&#160;</td>
			<td>Bio-Rad</td>
			<td>161-0142</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">TEMED</td>
			<td>Bio-Rad</td>
			<td>161-0800</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ammonium persulfate&#160;</td>
			<td>Sigma</td>
			<td>A3678-25G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">boric acid</td>
			<td>Sigma</td>
			<td>B7901-1KG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">saponin&#160;</td>
			<td>Sigma</td>
			<td>47036</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">sodium dodecyl sulfate&#160;</td>
			<td>Sigma</td>
			<td style="width:119px;">L337-500G</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">sodium phosphate (monobasic)</td>
			<td>Sigma</td>
			<td>04269-1KG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">sodium phosphate (dibasic)</td>
			<td>Sigma</td>
			<td>S5136-1KG</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Triton X-100</td>
			<td>Sigma</td>
			<td>X100-500ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">glycerol&#160;</td>
			<td>Sigma</td>
			<td>G9012-500ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">16% paraformaldehyde&#160;</td>
			<td>Electron Microscopy Sciences</td>
			<td>15710-S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">NaOH pellets&#160;</td>
			<td>EMD</td>
			<td>SX0590-3</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">15 ml centrifuge tubes</td>
			<td style="width:200px;">Any brand</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">dissecting tools&#160;</td>
			<td style="width:200px;">Any brand</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

a new clarification method to visualize biliary degeneration during liver metamorphosis in sea lamprey (petromyzon marinus)

Biliary atresia is a rare disease of infancy, with an estimated 1 in 15,000 frequency in the southeast United States, but more common in East Asian countries, with a reported frequency of 1 in 5,000 in Taiwan. Although much is known about the management of biliary atresia, its pathogenesis is still elusive. The sea lamprey (Petromyzon marinus) provides a unique opportunity to examine the mechanism and progression of biliary degeneration. Sea lamprey develop through three distinct life stages: larval, parasitic, and adult. During the transition from larvae to parasitic juvenile, sea lamprey undergo metamorphosis with dramatic reorganization and remodeling in external morphology and internal organs. In the liver, the entire biliary system is lost, including the gall bladder and the biliary tree. A newly-developed method called &#8220;CLARITY&#8221; was modified to clarify the entire liver and the junction with the intestine in metamorphic sea lamprey. The process of biliary degeneration was visualized and discerned during sea lamprey metamorphosis by using laser scanning confocal microscopy. This method provides a powerful tool to study biliary atresia in a unique animal model.

Several important developmental events occur in the hepatobiliary system during sea lamprey metamorphosis. The bile duct and the gall bladder undergo apoptosis and degenerate (Figure 1). Combining the modified clarification method and staining with liver cell marker cytokeratin 19 (CK19, present in both cholangiocytes and hepatocytes before and after metamorphosis13) and anti-apoptotic marker Bcl2 using confocal microscopy, the entire biliary system was captured along the Z-axis (Figur...

Watch this Scientific Journal Video about A New Clarification Method to Visualize Biliary Degeneration During Liver Metamorphosis in Sea Lamprey Petromyzon marinus at JoVE.com

A New Clarification Method to Visualize Biliary Degeneration During Liver Metamorphosis in Sea Lamprey Petromyzon marinus

Sea lamprey lose the gall bladder and bile ducts during metamorphosis, a process similar to human biliary atresia. A new fixation and clarification method (CLARITY) was modified to visualize the entire biliary tree using laser scanning confocal microscopy. This method provides a powerful tool to study biliary degeneration.

A New Clarification Method to Visualize Biliary Degeneration During Liver Metamorphosis in Sea Lamprey (Petromyzon marinus)

Biliary atresia is a rare disease of infancy, with an estimated 1 in 15,000 frequency in the southeast United States, but more common in East Asian ...

a-new-clarification-method-to-visualize-biliary-degeneration-during

Research

JoVE Journal

Biology

13.7K Views.  Michigan State University. Sea lamprey lose the gall bladder and bile ducts during metamorphosis, a process similar to human biliary atresia. A new fixation and clarification method (CLARITY) was modified to visualize the entire biliary tree using laser scanning confocal microscopy. This method provides a powerful tool to study biliary degeneration.

Video: A New Clarification Method to Visualize Biliary Degeneration During Liver Metamorphosis in Sea Lamprey Petromyzon marinus

Pyrosequencing: A Simple Method for Accurate Genotyping

Pharmacogenetic research benefits first-hand from the abundance of information provided by the completion of the Human Genome Project. With such a tremendous amount of data available comes an explosion of genotyping methods. Pyrosequencing(R) is one of the most thorough yet simple methods to date used to analyze polymorphisms. It also has the ability to identify tri-allelic, indels, short-repeat polymorphisms, along with determining allele percentages for methylation or pooled sample assessment. In addition, there is a standardized control sequence that provides internal quality control. This method has led to rapid and efficient single-nucleotide polymorphism evaluation including many clinically relevant polymorphisms. The technique and methodology of Pyrosequencing is explained.


Pyrosequencing(R) is one of the most thorough yet simple methods to date used to analyze polymorphisms. This method has led to rapid and efficient single-nucleotide polymorphism evaluation including many clinically relevant polymorphisms. The technique and methodology of Pyrosequencing is explained.

Pharmacogenetic research benefits first-hand from the abundance of information provided by the completion of the Human Genome Project. With such a ...

Method for Culture of Early Chick Embryos ex vivo (New Culture)

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ideal tool for studying  the formation and patterning of brain, neural tube, somite and heart primordia. Applications of chick embryo culture include electroporation of DNA or RNA constructs in order to analyze gene function, grafts of growth factor coated beads such as FGFs and BMPs , as well as whole mount in situ hybridization and immunohistochemistry. This video demonstrates the different steps in chick embryo culture; First, the embryo is explanted in saline. Then, the embryo is centered on a glass ring. The membranes surrounding the embryo are lifted along the walls of the ring. The ring is then placed in a culture dish containing a pool of albumine. The culture dish is sealed and placed in a humid chamber, where the embryo is cultured for up to 24 hrs. Finally, the embryo is removed from the ring, fixed and processed for further applications. A troubleshooting guide is also presented.

Method for Culture of Early Chick Embryos ex vivo New Culture

This video demonstrates New culture, a method by which chick embryos are cultured outside the egg for up to 24 hr. This method enables one to study early development (primitive streak to 14 som.), a period corresponding to E7-9 in mouse. Applications of this technique include electroporation, in situ hybridization and immunohistochemistry.

The chick embryo is a valuable tool in the study of early embryonic development. Its transparency, accessibility and ease of manipulation, make it an ...

Visually Mediated Odor Tracking During Flight in Drosophila

Flying insects use visual cues to stabilize their heading in a wind stream. Many animals additionally track odors carried in the wind. As such, visual stabilization of upwind tracking directly aids in odor tracking. But do olfactory signals directly influence visual tracking behavior independently from wind cues? Additionally, recent advances in olfactory molecular genetics and neurophysiology have motivated novel quantitative behavioral analyses to assess the behavioral influence of (e.g.) genetically inactivating specific olfactory activation circuits. We modified a magnetic tether system originally devised for vision experiments by equipping the arena with narrow laminar flow odor plumes. Here we focus on experiments that can be performed after a fly is tethered and is able to navigate in the magnetic arena. We show how to acquire video images optimized for measuring body angle, how to judge stable odor tracking, and we illustrate two experiments to examine the influence of visual cues on odor tracking.

Here we describe how to optimize the acquired video image for an olfactory magnetic-tether (OMT) apparatus. We also describe two sample experimental protocols for studying visuo-olfactory fusion.

Flying insects use visual cues to stabilize their heading in a wind stream. Many animals additionally track odors carried in the wind. As such, visual ...

RNAi-mediated Gene Knockdown and In Vivo Diuresis Assay in Adult Female Aedes aegypti Mosquitoes

This video protocol demonstrates an effective technique to knockdown a particular gene in an insect and conduct a novel bioassay to measure excretion rate. This method can be used to obtain a better understanding of the process of diuresis in insects and is especially useful in the study of diuresis in blood-feeding arthropods that are able to take up huge amounts of liquid in a single blood meal. 
This RNAi-mediated gene knockdown combined with an in vivo diuresis assay was developed by the Hansen lab to study the effects of RNAi-mediated knockdown of aquaporin genes on Aedes aegypti mosquito diuresis1. 
The protocol is setup in two parts: the first demonstration illustrates how to construct a simple mosquito injection device and how to prepare and inject dsRNA into the thorax of mosquitoes for RNAi-mediated gene knockdown. The second demonstration illustrates how to determine excretion rates in mosquitoes using an in vivo bioassay.

RNAi-mediated Gene Knockdown and In Vivo Diuresis Assay in Adult Female Aedes aegypti Mosquitoes

In this protocol we combine RNAi-mediated gene silencing with an in vivo diuresis assay to study the effects knockdown of genes of interest has on mosquito fluid excretion.

This video protocol demonstrates an effective technique to knockdown a particular gene in an insect and conduct a novel bioassay to measure excretion ...

Do-It-Yourself Device for Recovery of Cryopreserved Samples Accidentally Dropped into Cryogenic Storage Tanks

Liquid nitrogen is colorless, odorless, extremely cold (-196 &deg;C) liquid kept under pressure. It is commonly used as a cryogenic fluid for long term storage of biological materials such as blood, cells and tissues 1,2. The cryogenic nature of liquid nitrogen, while ideal for sample preservation, can cause rapid freezing of live tissues on contact - known as 'cryogenic burn'2, which may lead to severe frostbite in persons closely involved in storage and retrieval of samples from Dewars. Additionally, as liquid nitrogen evaporates it reduces the oxygen concentration in the air and might cause asphyxia, especially in confined spaces2.
In laboratories, biological samples are often stored in cryovials or cryoboxes stacked in stainless steel racks within the Dewar tanks1. These storage racks are provided with a long shaft to prevent boxes from slipping out from the racks and into the bottom of Dewars during routine handling. All too often, however, boxes or vials with precious samples slip out and sink to the bottom of liquid nitrogen filled tank. In such cases, samples could be tediously retrieved after transferring the liquid nitrogen into a spare container or discarding it. The boxes and vials can then be relatively safely recovered from emptied Dewar. However, the cryogenic nature of liquid nitrogen and its expansion rate makes sunken sample retrieval hazardous. It is commonly recommended by Safety Offices that sample retrieval be never carried out by a single person. Another alternative is to use commercially available cool grabbers or tongs to pull out the vials3. However, limited visibility within the dark liquid filled Dewars poses a major limitation in their use.
In this article, we describe the construction of a Cryotolerant DIY retrieval device, which makes sample retrieval from Dewar containing cryogenic fluids both safe and easy.

Here we present a low cost, durable cryotolerant device for sample retrieval from Dewar tanks filled with liquid nitrogen. The ease of construction and modular design of the device makes the process of sample retrieval from cryogenic tanks safe and easy.

Liquid nitrogen is colorless, odorless, extremely cold (-196 &deg;C) liquid kept under pressure. It is commonly used as a cryogenic fluid for long term ...

Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization

Fluorescent in situ hybridization using DNA probes on 3-dimensionally preserved nuclei followed by 3D confocal microscopy (3D DNA FISH) represents the most direct way to visualize the location of gene loci, chromosomal sub-regions or entire territories in individual cells. This type of analysis provides insight into the global architecture of the nucleus as well as the behavior of specific genomic loci and regions within the nuclear space. Immunofluorescence, on the other hand, permits the detection of nuclear proteins (modified histones, histone variants and modifiers, transcription machinery and factors, nuclear sub-compartments, etc). The major challenge in combining immunofluorescence and 3D DNA FISH is, on the one hand to preserve the epitope detected by the antibody as well as the 3D architecture of the nucleus, and on the other hand, to allow the penetration of the DNA probe to detect gene loci or chromosome territories 1-5. Here we provide a protocol that combines visualization of chromatin modifications with genomic loci in 3D preserved nuclei.

Here we describe a protocol for simultaneous detection of histone modifications by immunofluorescence and DNA sequences by DNA FISH followed by 3D microscopy and analyses (3D immuno-DNA FISH).

Fluorescent in situ hybridization using DNA probes  on 3-dimensionally preserved nuclei followed by 3D confocal microscopy (3D DNA  FISH) represents the ...

High Throughput Microinjections of Sea Urchin Zygotes

Microinjection into cells and embryos is a common technique that is used to study a wide range of biological processes. In this method a small amount of treatment solution is loaded into a microinjection needle that is used to physically inject individual immobilized cells or embryos. Despite the need for initial training to perform this procedure for high-throughput delivery, microinjection offers maximum efficiency and reproducible delivery of a wide variety of treatment solutions (including complex mixtures of samples) into cells, eggs or embryos. Applications to microinjections include delivery of DNA constructs, mRNAs, recombinant proteins, gain of function, and loss of function reagents. Fluorescent or colorimetric dye is added to the injected solution to enable instant visualization of efficient delivery as well as a tool for reliable normalization of the amount of the delivered solution. The described method enables microinjection of 100-400 sea urchin zygotes within 10-15 min.

Microinjection is a common technique used to deliver DNA constructs, mRNAs, morpholino antisense oligonucleotides or other treatments into eggs, embryos, and cells of various species.

Microinjection into cells and embryos is a common technique that is used to study a wide range of biological processes. In this method a small amount of ...

A Method for Extracting Pigments from Squid Doryteuthis pealeii

Cephalopods can undergo rapid and adaptive changes in dermal coloration for sensing, communication, defense, and reproduction purposes. These capabilities are supported in part by the areal expansion and retraction of pigmented organs known as chromatophores. While it is known that the chromatophores contain a tethered network of pigmented granules, their structure-function properties have not been fully detailed. We describe a method for isolating the nanostructured granules in squid Doryteuthis pealeii chromatophores and demonstrate how their associated pigments can be extracted in acidic solvents. To accomplish this, the chromatophore containing dermal layer is first manually isolated using a superficial dissection, and the pigment granules are removed using sonication, centrifugation, and washing cycles. Pigments confined within the purified granules are then extracted via acidic methanol solutions, leaving nanostructures with smaller diameters that are void of visible color. This extraction procedure produces a 58% yield of soluble pigments isolated from granules. Using this method, the composition of the chromatophore pigments can be determined and used to provide insight into the mechanism of adaptive coloration in cephalopods.

A Method for Extracting Pigments from Squid Doryteuthis pealeii

A protocol for the extraction of pigments from the nanostructured granules in squid Doryteuthis pealeii chromatophores is presented.

Cephalopods can undergo rapid and adaptive changes in dermal coloration for sensing, communication, defense, and reproduction purposes. These capabilities ...

Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus

This work describes the whole-mount immunohistochemistry staining method in detail, using neurofilament protein antibody to label the innervation of the biliary tract in Suncus murinus (S. murinus&#160;). First, the specimen was dissected from S. murinus and fixed in 4% paraformaldehyde (PFA). Second, an enzymatic treatment and potential endogenous peroxidase inactivation were performed. The specimen was then exposed to the primary antibody, anti-neurofilament protein antibody, for 3-6 days. It was then incubated with the secondary antibody conjugated with horseradish peroxidase. The color reaction was revealed by reacting the specimen with a 3,3&#39;-diaminobenzidine (DAB) substrate. This method can be applied to analyze the innervation of all visceral organs. Furthermore, this protocol can also be adapted to test other neuronal antibodies, but optimization of the antibodies should be done first. This method was originally introduced by Kuratani and Tanaka1,2,3.

Using a Whole-mount Immunohistochemical Method to Study the Innervation of the Biliary Tract in Suncus murinus

A whole-mount immunohistochemical approach, to visualize neurofilament protein expression in the extrahepatic biliary tract in Suncus murinus. is presented here. This protocol can be used to analyze the innervation of all visceral organs in S. murinus or other species.

This work describes the whole-mount immunohistochemistry staining method in detail, using neurofilament protein antibody to label the innervation of the ...

Broth Microdilution In Vitro Screening: An Easy and Fast Method to Detect New Antifungal Compounds

Fungal infections have become an important medical condition in the last decades, but the number of available antifungal drugs is limited. In this scenario, the search for new antifungal drugs is necessary. The protocol reported here details a method to screen peptides for their antifungal properties. It is based on the broth microdilution susceptibility test from the Clinical and Laboratory Standards Institute (CLSI) M27-A3 guidelines with modifications to suit the research of antimicrobial peptides as potential new antifungals. This protocol describes a functional assay to evaluate the activity of antifungal compounds and may be easily modified to suit any particular class of molecules under investigation. Since the assays are performed in 96-well plates using small volumes, a large-scale screening can be completed in a short amount of time, especially if carried out in an automation setting. This procedure illustrates how a standardized and adjustable clinical protocol can help the bench-work pursuit of new molecules to improve the therapy of fungal diseases.

Broth Microdilution In Vitro Screening: An Easy and Fast Method to Detect New Antifungal Compounds

An easy and adaptable broth microdilution method for screening antifungal compounds and extracts.