title: Implementation of immunohistochemistry on frozen ear notch tissue samples in diagnosis of bovine viral diarrhea virus in persistently infected cattle.
abstract: BACKGROUND
  Bovine viral diarrhea is a contagious disease of domestic and wild ruminants and one of the most economically important diseases in cattle. Bovine viral diarrhea virus belongs to the genus Pestivirus, within the family Flaviviridae. The identification and elimination of the persistently infected animals from herds is the initial step in the control and eradication programs. It is therefore necessary to have reliable methods for diagnosis of bovine viral diarrhea virus. One of those methods is immunohistochemistry. Immunohistochemistry on formalin fixed, paraffin embedded tissue is a routine technique in diagnosis of persistently infected cattle from ear notch tissue samples. However, such technique is inappropriate due to complicated tissue fixation process and it requires more days for preparation. On the contrary, immunohistochemistry on frozen tissue was usually applied on organs from dead animals. In this paper, for the first time, the imunohistochemistry on frozen ear notch tissue samples was described.
  
  
  RESULTS
  Seventeen ear notch tissue samples were obtained during the period 2008-2009 from persistently infected cattle. Samples were fixed in liquid nitrogen and stored on -20°C until testing. Ear notch tissue samples from all persistently infected cattle showed positive results with good section quality and possibility to determinate type of infected cells.
  
  
  CONCLUSIONS
  Although the number of samples was limited, this study indicated that immunohistochemistry on formalin fixed paraffin embedded tissue can be successfully replaced with immunohistochemistry on frozen ear notch tissue samples in diagnosis of persistently infected cattle.
authors.affiliation: Croatian Veterinary Institute, Savska cesta, 143, 10000 Zagreb, Croatia. bedekovic@veinst.hr
authors.forename: Tomislav
authors.initials: T
authors.lastname: Bedeković
authors.forename: Nina
authors.initials: N
authors.lastname: Lemo
authors.forename: Ivana
authors.initials: I
authors.lastname: Lojkić
authors.forename: Ana
authors.initials: A
authors.lastname: Beck
authors.forename: Mirko
authors.initials: M
authors.lastname: Lojkić
authors.forename: Josip
authors.initials: J
authors.lastname: Madić
mesh_terms: D000818:Animals; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000175:diagnosis*; D002417:Cattle; D001908:Diarrhea Viruses, Bovine Viral / Q000302:isolation & purification*; D004431:Ear, External / Q000821:virology*; D005260:Female; D007150:Immunohistochemistry / Q000379:methods / Q000662:veterinary*; D011237:Predictive Value of Tests; D014021:Tissue Preservation / Q000662:veterinary