Incubation periods of hamsters intracerebrally inoculated with unbound and soil-bound PrP^Sc.

<p>Incubation periods of hamsters intracerebrally inoculated with unbound and soil-bound PrP^Sc.</p

Repeated cycles of drying and wetting alter the resistance of HY PrP^Sc to digestion with proteinase K.

<p>Western blot (A) and quantification (B) of PK digested HY PrP^Sc alone or adsorbed to soil before (Dry 0) and after 1 (Dry 1) and 10 (Dry 10) serial rounds of drying and wetting. Migration of 29 and 21 kDa molecular weight marker is indicated on the right of the Western blot. Star indicates significant difference (p<0.05; n = 3) between treated and untreated sample.</p

Reduced PMCA conversion coefficient of SCL-HY after repeated cycles of drying and wetting.

<p>Western blot of PMCA amplification of 10-fold serial dilutions of standardized SCL-HY PrP^Sc before (Dry 0) or after 10 (Dry 10) rounds of drying and wetting. Samples in replicates (n = 3) were tested. Migration of 29 and 21 kDa molecular weight marker is indicated on the right of the Western blot.</p

Influence of repeated cycles of drying and wetting on proteinase K resistance and amplification efficiency of DY TME.

<p>Western blot (A and B) and quantification (C and D) of PK digested and PMCA amplification (3 rounds) of DY PrP^Sc alone or adsorbed to SCL before (Dry 0) and after 1 (Dry 1) and 10 (Dry 10) serial rounds of drying and wetting. Negative PMCA samples were diluted from corresponding PMCA seeding with a dilution factor of 80. Migration of 29 and 19 kDa molecular weight marker is indicated on the right of the Western blot. Star indicates significant difference (p<0.05; n = 3) between treated and untreated sample.</p

Reduced total protein abundance in HY TME brain homogenate.

<p>UV scanned polyacrylamide gel stained with SYPRO Ruby (A) and quantification of total proteins (B). Samples were not digested with proteinase K. Star indicates significant difference (p<0.05; n = 3) between treated and untreated sample.</p

Influence of repeated cycles of drying and wetting on proteinase K resistance and amplification efficiency of elk CWD.

<p>Western blot (A and B) and quantification (C and D) of PK digested and PMCA amplification (3 rounds) of elk CWD PrP^Sc alone or adsorbed to SCL before (Dry 0) and after 1 (Dry 1) and 10 (Dry 10) serial rounds of drying and wetting. Migration of 29 and 21 kDa molecular weight marker is indicated on the right of the Western blot. Star indicates significant difference (p<0.05; n = 3) between treated and untreated sample.</p

Preparation of soil bound HY TME, DY TME^a, and elk CWD^a PrP^Sc.

<p>^a SCL bound DY TME and elk CWD PrP^Sc were prepared with the same soil to brain ratio and in the same condition as SCL bound HY TME. HY TME was also used for animal bioassay</p><p>^b BH, 10% brain homogenate.</p><p>^c SiO_2-HA, SiO_2-humic acid.</p><p>^d The amount of samples used for PMCA was expressed as weight of soil—equivalent volume of soil solution.</p><p>^e Due to the performance challenge, PMCA substrate was added to the soil pellets of weight as indicated in the table.</p><p>Preparation of soil bound HY TME, DY TME<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004638#t001fn001" target="_blank">^a</a>, and elk CWD<a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004638#t001fn001" target="_blank">^a</a> PrP^Sc.</p

Repeated cycles of drying and wetting extend the incubation period of prion infection.

<p>Survival curve of hamsters inoculated with untreated (0) or drying/wetting treated (1 or 10) HY (A), SCL-HY (B), SiO_2-HY (C), and SLS-HY (D). 5 hamsters (n = 5) were used for each sample. P0/1 or P0/10 designated p value derived from the comparison of incubation periods of hamsters inoculated with untreated (0) and 1 or 10 cycle(s) of drying and wetting treated samples.</p

Repeated cycles of drying and wetting reduced the PMCA conversion efficiency of soil bound HY TME.

<p>Western blot (A) and quantification (B) of PMCA amplification (1 round) of HY PrP^Sc alone or adsorbed to soil before (Dry 0) and after 1 (Dry 1) and 10 (Dry 10) serial rounds of drying and wetting. Migration of 29 and 21 kDa molecular weight marker is indicated on the right of the Western blot. Star indicates significant difference (p<0.05; n = 3) between treated and untreated sample.</p

Sorption of HY to soil reduces the number of wet dry cycles that result in a decrease in PMCA conversion activity.

<p>Western blot (A and B) and quantification (C and D) of PMCA amplification (1 round) of HY PrP^Sc alone or adsorbed to SCL after 1, 3, 5, 7, and 10 serial rounds of drying and wetting. Migration of 29 and 21 kDa molecular weight marker is indicated on the right of the Western blot. Star indicates significant difference (p<0.05; n = 3) between multiple drying/wetting treated and single drying/wetting treated sample.</p