Novel determination merhod of size of virus in solution using cuprammonium regenerated cellulose membrane(BMM).

We intended to propose a novel ultrafiltration method using BMM for determination of virion size in solution and for evaluation of the size of aggregate being composed of several virions and content cocurrently. We assumed that the pore structure of BMM was represented by multilayer structure and consequently multi-step ultrafiltration occured and that BMM did not adsorb protein and removing virions was determined only by the geometrical sizes of virion and pore. The equation derived theoretically wasΦ= (0.5d/2.303) (2v/2rf) C'-D (1) where Φ is the virus logarithmic rejection coefficient and, d, 2v and 2rf are membrane thickness, particle size and mean pore size, respectively, and C' and D are constants. The reliability of eq 1 was proved experimentally using gold particles with various sizes and Japanese encephalitis virus (JEV). The values of C' and D for JEV were nearly constant for BMMs with various 2rf. The sizes of the aggregates of Φx 74 virions and Hepatitis B type virus were determined through above method as 62 nm and 44 nm, respectively.