Detection of Influenza Virus Particles in Throat Washings by Electron Microscopy

Abstract

Although the symptomatology of influenza is well known and fairly typical in most cases, the exact diagnosis is often presumptive because of the technical difficulties in performing laboratory tests. We have recently developed a method for concentrating and processing throat washings to provide a cell block which can be sectioned for ultrastructural study. We have used this technique for studying the throat washings from five sero-logically proven patients with Influenza A2 Hong Kong infection. Two ml of throat washings were mixed with 0. 5 ml of a fixative containing 2% acrolein, 3% glutaraldehyde in phosphate buffer at pH 7. 2 in a centrifuge tube. A disc of filter paper (Whatman #41 ashless) 5 mm in diameter was placed in the centrifuge tube, and the samples were centrifuged at 18,000 rpm for one hour.