Quantification of adenovirus particles.

A physical method for quantification of the adenovirus was tested. It implies a centrifugation of the clarified or chloroform- (or freon-) treated crude virus suspension (0.5 ml) in a gentle sucrose gradient, following the analysis in a sensitive UV flow photometer and calculation of virus mass. The result (micrograms/ml) is obtained after about 1 h. The sensitivity of detection at wavelength 254 nm, 278 nm and 226 nm was compared. Virus yield of several serotypes from monolayer cultures of FL-cells was determined in a range of < 0.1 to 7 micrograms/ml. The ratio of infectious to physically complete virus (about the 770S component), the influence of freezing and thawing, storing at 4 degrees C and the effectiveness of concentration steps were also determined. There was no significant difference between the sucrose density gradient method (sedimentation rate) and the density equilibrium ultracentrifugation in a CsCl gradient.