The freezing curves for the low-density isolates were similar to the unprocessed samples, but shifted to slightly colder (~1 °C) temperatures, indicating that a large fraction of the Snomax INSs were recovered in the low-density isolate, but not all. For the high-density isolates, one of the freezing curves overlaps with the ultrapure water blanks, but two of the freezing curves were shifted to warmer temperatures at low INS concentrations. This suggests that the high-density isolate was contaminated by a relatively small concentration of Snomax in some, but not all, experimental replicates.