The modified dilution assay aims to partition phytoplankton mortality into virus- versus grazing-induced fractions and has previously been applied to several different environments to determine viral lysis rates of natural phytoplankton. The method involves creating a gradient of both grazing and viral lysis by dilution with different proportions of grazer- and virus-free filtrate, and assessing the subsequent impact on phytoplankton growth rates.Kimmance, S. A., and C. P. D. Brussaard. 2010. Estimation of viralinduced phytoplankton mortality using the modified dilution method, p. 65\u201373. In S. W. Wilhelm, M. G. Weinbauer, and C. A. Suttle [eds.], Manual of Aquatic Viral Ecology. ASLO.