The manufacturer-provided buffer was discarded and sterile PBS was used and then added to the macrofoam sponge component of the BiSKit. Once the PBS had adequately absorbed to the macrofoam sponge, the sampler was unscrewed from the module and was traversed about the surface area of interest (ca. 1 m 2 ), first in a horizontal fashion, then vertically, and finally in a diagonal sweeping pattern.
Source: wiktionary