Testing of Freedom of Extraneous Viral Agents in Materials of Biological Origin: This is to detect viral contamination in cell stock. Test sample is inoculated onto different types of cell cultures and passaged twice and observed for Viral Cytopathic Effect (CPE). Depending on the required viruses, there may be a need to examine for non-cytopathic virus presence also using immuno-cytochemistry. This test takes two to three weeks to complete. Please contact us for more information and if further discussion on your specific need is required.