Avian influenza virus RNA extraction from tissue and swab material.

The efficient extraction and purification of viral RNA are critical for downstream molecular applications, whether it is the sensitive and specific detection of virus in clinical samples, virus gene cloning and expression, or quantification of the avian influenza (AI) virus by molecular methods from experimentally infected birds. Samples can generally be divided into two types: enriched (e.g., virus stocks) and clinical. Clinical type samples, which may be tissues or swab material, are the most difficult to process due to the complex sample composition and possibly low virus titers. In this chapter, two well-established procedures for the isolation of AI virus RNA from common clinical specimen types and enriched virus stocks for further molecular applications will be presented.