U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Virus and Prion Research: Ames, IA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area Ames, Iowa National Animal Disease Center Virus and Prion Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Nicholson, Ericitem
                                            Hamir, Amiraliitem
                                            Kunkle, Robert
  Submitted to: United States Animal Health Association Proceedings
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 8/1/2006
                                    Publication  Date: 10/12/2006
                                    Citation: Nicholson, E.M., Hamir, A.N., Kunkle, R.A. 2006. Detection of PrP**sc in formalin-fixed tissues by Western blot [abstract]. United States Animal Health Association. p. 332.Interpretive Summary:
                                Technical Abstract: Formalin fixation is the most prevalent form of tissue preservative.  As such, formalin fixed tissue represents an important source of archival material for study.  Formalin fixation requires little environmental control and preserves the cellular architecture of a wide range of tissues, an important aspect for the accurate and reliable diagnosis of transmissible spongiform encephalopathies (TSEs) by immunohistochemistry (IHC), considered by some to be the gold standard for diagnosis of TSEs. Alternatively, freezing of tissue samples is ideal for Western blot analysis but results in disruption of cellular architecture.  Both methods are employed in a comprehensive diagnosis of a TSE.
   Virtually all diagnostic methods for TSEs rely on immunodetection of the disease associated form of the prion protein (PrP**Sc).  Since the prion protein is a host encoded protein, an animal affected with a prion disease will have both the normal cellular form of the prion protein (PrP*C) and PrP*Sc.  To date no commercially available antibody can distinguish these two isoforms of the protein.  IHC relies on a highly trained and experienced user to distinguish disease associated staining from background PrP*C while Western blot is dependent upon limited digestion of the sample with proteinase K removing PrP*C leaving only PrP*Sc.  These two methods have different strengths and weaknesses and as such are best used in a complementary manner.  
   Under field conditions, the only available tissue samples may be formalin fixed.  A method for detecting PrP*Sc in formalin fixed tissues would allow analysis of numerous archived samples by Western blot, would simplify preservation of field collected samples for TSE detection, allow both Western blot and IHC analysis of the same preserved sample, and allow adjacent regions of brain to be analyzed by both IHC and Western blot enhancing the study of TSEs.
   Approaches to prepare formalin fixed tissues for Western blot suitable for various proteins have been reported, however, none are applicable to the detection of PrP*Sc as they employ conditions known to render PrP*Sc proteinase K sensitive.  Here we present an approach that recovers the signal of PrP*Sc while retaining the associated proteinase K resistance such that PrP*C signal may be removed via proteinase K digestion.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov