Snell et al. [15,22] standardized toxicity tests with freshwater rotifers. Three experiments were
conducted with four replicates at five different QS concentrations ranging from 0 to 25.5 Min 24-well
plates at 1 mL per well. Wells were covered to prevent evaporation. Ten to twelve rotifers were
transferred into each well and were incubated for 24 h. The well plates were examined under the
stereomicroscope for rotifer mortality after 24 h to calculate LC50s (the LC50 is the concentration that
causes mortality to 50% of the population). The number of live and dead rotifers was recorded, with
rotifers not moving for 10 s regarded as dead.