Simple procedures to obtain exogenous internal controls for use in RT-PCR detection of bovine pestiviruses.

Pestiviruses are ubiquitous pathogens of cattle and frequent adventitious viruses in biologicals. Furthermore, it has been suggested that these agents might be related to infantile gastroenteritis and microencephaly. Since the virus is highly prevalent in fetal bovine serum, the risk of contamination is high in most laboratories. Thus, the implementation of detection methods in all laboratories is of worth. Despite continuous surveillance, these agents have been detected in cell lines, fetal bovine serum, live and inactivated animal and human vaccines and interferon for human use. In this report, DNA and RNA internal controls (ICs) which can be implemented in laboratories with minimal equipment are described. The developed standards can be added before RNA purification, allowing to monitor all steps of the protocol (viral RNA extraction, reverse transcription and cDNA amplification). It is shown that inhibitory effects that could lead to decreased sensitivity can be minimized by controlling the amount of mimic molecules added to the samples. A method to avoid the problem of DNA traces present in in vitro transcribed RNA preparations is provided.