The objectives of this study were to evaluate differences in prion adsorption and replication efficiency as a function of adsorption solution and to evaluate desorption and replication of soil-bound prions over time periods up to 1 year. We studied adsorption and desorption of HY TME hamster PrPSc to a range of soils and soil minerals for up to one year in various aqueous solutions. We also applied a previously developed semi-quantitative protein misfolding cyclic amplification protocol to assay variance in the replication efficiency of PrPSc bound to soil minerals with respect to adsorption solution and aging time. A key objective of this study was to determine if adsorption solution chemistry significantly affects prion protein adsorption and soil-bound prion replication. Prions could exist in the environment in a range of aqueous solutions from high ionic strength biological solutions originating from excreta or an infected mortality to relatively dilute surface or NSC727447 ground waters. Important determinants of the solution chemistry of ��natural�� prion-soil interactions could include soil and water composition as well as precipitation and other weather-related factors. Although previous studies evaluating prion adsorption to soil have used a wide range of adsorption solutions, only two studies have compared PrP adsorption as a function of solution chemistry, both using PrP sources in the absence of a biological matrix. In the present study, we used infectious brain homogenate to study PrP adsorption and desorption as well as soil-bound prion replication. We found only slight differences in PrPSc adsorption to SiO2 powder and bentonite clay in DPBS, NaCl, and CaCl2. Differences in SiO2- and bentonite-bound prion replication were also slight between solutions, although it should be noted that small differences in PMCA amplification can be indicative of much larger differences in infectious titer. Moreover, adsorption solution significantly affected humic acid-bound prion replication, with SiO2-HA samples incubated in DI water showing complete inhibition of replication. Sand-bound prion replication also varied with adsorption solution, although all solutions Ochratoxin A generated sand-bound prions capable of replication.