Quantification of recombinant core-like particles of bluetongue virus using immunosorbent electron microscopy

Immunosorbent electron microscopy was used to quantify recombinant baculovi rus-generated bluetongue virus (BTV) core-like particles (CLP) in either pu rified preparations or lysates of recombinant baculovirus-infected cells. T he capture antibody was an anti-BTV VP7 monoclonal antibody. The CLP concen tration in purified preparations was determined to be 6.6 x 10(15) particle s/l. CLP concentration in lysates of recombinant baculovirus-infected cells was determined at various times post-infection and shown to reach a value of 3 x 10(15) particles/l of culture medium at 96 h post-infection. The res ults indicated that immunosorbent electron microscopy, aided by an improved particle counting method, is a simple, rapid and accurate technique for th e quantification of virus and virus-like particles produced in large scale in vitro systems. (C) 1999 Elsevier Science B.V. All rights reserved.