Location: Avian Disease and Oncology Laboratory
Title: Use of polymerase chain reaction in detection of Marek’s disease and reticuloendotheliosis viruses in formalin-fixed, paraffin-embedded tumorous tissues Authors
Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 19, 2013
Publication Date: December 31, 2013
Citation: Cao, W., Mays, J.K., Dunn, J.R., Fulton, R.M., Silva, R.F., Fadly, A.M. 2013. Use of polymerase chain reaction in detection of Marek’s disease and reticuloendotheliosis viruses in formalin-fixed, paraffin-embedded tumorous tissues. Avian Diseases. 57:785-789. Interpretive Summary: Marek’s disease virus (MDV) and reticuloendotheliosis virus (REV) are viruses that can cause cancer-like diseases and other production problems in poultry. Diagnosis of such diseases is currently based on gross and microscopic examinations of affected tissues. However, in some cases, further biological or molecular testing of such tissues may be required to confirm the diagnosis. Such tests require use of frozen samples, and therefore, such samples must be shipped to the laboratory on dry-ice, hazardous goods. We developed a simple DNA-based test named polymerase chain reaction (PCR) using tissues that have been treated (fixed) with formalin, substance that preserve tissues, and stored in paraffin blocks for various time intervals at room temperature. Our results indicate that PCR of formalin fixed and paraffin-embedded tissues is a simple and valuable tool that can be used to identify MDV and REV infections. This information should be useful to poultry breeders and growers as well as poultry disease diagnosticians, as the new method is a good alternative to the expensive and cumbersome biological, molecular, or immunohistochemical assays that are being used now to confirm the diagnosis of MDV and REV; also, the new method alleviated the need for shipping frozen tissues to diagnostic laboratory.
Technical Abstract: A simple polymerase chain reaction (PCR) method was developed for the diagnosis of Marek’s disease (MD) and reticuloendotheliosis (RE) in formalin-fixed paraffin-embedded (FFPE) tissues; and for the diagnosis of MD in tissues only preserved in 10% neutral buffered formalin. MD virus (MDV) and RE virus (REV) were detected in FFPE tissues stored for over 20 years. MDV was also detected in tissues only preserved in formalin for up to 6 months. The data indicate that PCR of formalin fixed (FF) and FFPE tissues is a simple and valuable tool that can be used to identify MD and RE infection. The method described in this paper is a good alternative to any biological, molecular, or immunohistochemical assay to confirm the diagnosis of MD and RE, as it does not require shipping frozen tissues to diagnostic laboratory.