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Virology Testing (adventitious virus)

BioReliance performs a series of biosafety assays designed to detect species specific and adventitious viruses in working cell banks, master cell banks, virus seed stock, raw materials and final products.


Each assay method is fully validated in accordance with ICH Q2 (R1) guidelines and EP 2.6.21. Assays are available for human viruses, respiratory viruses, porcine viruses, simian viruses, canine, murine and many more. Development and validation services also are available for emerging viruses. 


BioReliance CRO’s virology testing services provide reassurance that the production of biologicals is free of contamination through assays including 

In vitro assays - Virology Testing



  • Mouse antibody production test (MAP)
  • Hamster antibody production test (HAP)
  • Rodent antibody production test (RAP)
  • Custom assays based on your virology testing needs


Retrovirus Testing

  • Co-cultivation (murine, ecotropic, amphotropic and rodent)
  • PCR/RT-PCR detection of endogenous and adventitious agents Direct and extended XC plaque assay
  • Direct and extended S+L- focus assay (mink, feline)
  • Amplification in Mus Dunni cells
  • Transmission Electron Microscopy (TEM)


To see our virology testing services, use the search tool to the right or click here.


 Why does virology testing need to be performed on biologicals?

When production of a biotechnology product or biological is derived from mammalian cell lines, contamination by endogenous and adventitious viruses can occur during the manufacturing process. For example, many cell lines are grown in the presence of fetal bovine serum raising the possibility of a native bovine virus contaminating the end product. 


The most common assays are in vitro virology tests in which the agent is inoculated into susceptible cell lines such as Vero cells, and the readout is a visible cytopathic effect, often called CPE in the literature. 


Not all viruses show CPEs, so we recommend secondary detection methods like those outlined above.  Below we detail a few common secondary virology testing methods.  To see our description of other assays please follow the links above or just use our assay search engine above and to the right.


Quantitative PCR Testing to Detect Adventitious Virus

BioReliance performs quantitative PCR tests designed to detect adventitious and endogenous viruses in cell banks, virus seed stock, raw materials and final products.  Assays are available for:

  • human viruses
  • respiratory viruses
  • porcine viruses
  • simian viruses
  • canine viruses
  • murine and many more specific target PCRs. 


The BioReliance has broad experience in virology testing and is available to provide guidance in protocol design for the most appropriate collection, preparation and evaluation of biologic samples to ensure sample integrity for PCR detection of adventitious virus.


Retrovirus Testing Services from BioReliance 

Adventitious viruses are often thought of as purely retroviruses.  Retroviruses are unique in that they can integrate into the host genome making them difficult to detect by normal methods.

To address this, the BioReliance provides a wide range of retrovirus detection testing services including:

  • XC plaque assay
  • S+L- focus assay
  • PERT
  • Transmission electron microscopy (TEM)
  • Co-cultivation assays (murine, ecotropic, amphotropic and rodent)


Consult with our experts to determine the best methods for testing your therapeutics for the presence of retroviruses.


Co-cultivation Assays for Adventitious Virus

Co-cultivation of production cells at the limit of the in vitro age is an assay we offer to test for latent retroviruses for our clients.  Essentially, your production cells are plated along with susceptible cell lines that exhibit stronger phenotypic CPE when the virus enters them.  Thus, viruses that are expressed as non-infectious particles or exhibit low level of expression in production cells are detected. 


Contact us to consult about specific testing for retroviruses by co-cultivation assays.