Reduction in standard error in log<sub>10</sub> SD50 estimates as a function of dilution interval and replicate number.

<p>(A), (C) Standard error (SE) in calculating log<sub>10</sub> SD50/mg for 10-, 5- and 2-fold dilution series in ED RT-QuIC assays performed for PD and DLB BHs, respectively. (B), (D) Comparative plot showing SE in log<sub>10</sub> SD50/mg for 10-, and 2-fold dilution series for 4, 8 and 12 replicates in ED assays performed for PD and DLB BHs, respectively. SE in SK-based log10 SD50 estimates was calculated as described earlier (see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1012554#sec010" target="_blank">Methods</a>). In each case, colored circles represent SE from triplicate ED assays with horizontal bar showing the mean value.</p> <p>(DOCX)</p>