<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Christina M. Carlson</dc:contributor>
  <dc:contributor>Aaron R. Morawski</dc:contributor>
  <dc:contributor>Alyson Manthei</dc:contributor>
  <dc:contributor>Neil R. Cashman</dc:contributor>
  <dc:creator>Christopher J. Johnson</dc:creator>
  <dc:date>2015</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Studies to understanding interspecies transmission of transmissible spongiform encephalopathies (TSEs, prion diseases) are challenging in that they typically rely upon lengthy and costly&amp;nbsp;&lt;/span&gt;&lt;i&gt;in vivo&lt;/i&gt;&lt;span&gt;&amp;nbsp;animal challenge studies. A number of&amp;nbsp;&lt;/span&gt;&lt;i&gt;in vitro&lt;/i&gt;&lt;span&gt;&amp;nbsp;assays have been developed to aid in measuring prion species barriers, thereby reducing animal use and providing quicker results than animal bioassays. Here, we present the protocol for a rapid&amp;nbsp;&lt;/span&gt;&lt;i&gt;in vitro&lt;/i&gt;&lt;span&gt;prion conversion assay called the conversion efficiency ratio (CER) assay. In this assay cellular prion protein (PrP&lt;/span&gt;&lt;span&gt;C&lt;/span&gt;&lt;span&gt;) from an uninfected host brain is denatured at both&amp;nbsp;&lt;/span&gt;&lt;a class="contextual_link" title="Making Solutions in the Laboratory, a JoVE Science Education video explaining more about about the context of pH" href="http://www.jove.com/science-education/5030/making-solutions-in-the-laboratory" data-show-preview="5030" data-title="Making Solutions in the Laboratory"&gt;pH&lt;/a&gt;&lt;span&gt;&amp;nbsp;7.4 and 3.5 to produce two substrates. When the pH 7.4 substrate is incubated with TSE agent, the amount of PrP&lt;/span&gt;&lt;span&gt;C&lt;/span&gt;&lt;span&gt;&amp;nbsp;that converts to a proteinase K (PK)-resistant state is modulated by the original host&amp;rsquo;s species barrier to the TSE agent. In contrast, PrP&lt;/span&gt;&lt;span&gt;C&lt;/span&gt;&lt;span&gt;&amp;nbsp;in the pH 3.5 substrate is misfolded by any TSE agent. By comparing the amount of PK-resistant prion protein in the two substrates, an assessment of the host&amp;rsquo;s species barrier can be made. We show that the CER assay correctly predicts known prion species barriers of laboratory mice and, as an example, show some preliminary results suggesting that bobcats (&lt;/span&gt;&lt;i&gt;Lynx rufus&lt;/i&gt;&lt;span&gt;) may be susceptible to white-tailed deer (&lt;/span&gt;&lt;i&gt;Odocoileus virginianus&lt;/i&gt;&lt;span&gt;) chronic wasting disease agent.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.3791/52522</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>JoVE</dc:publisher>
  <dc:title>Assessing transmissible spongiform encephalopathy species barriers with an &lt;i&gt;in vitro&lt;/i&gt; prion protein conversion assay</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>