The spatial information preservation method: Sampling the nanoscale spatial distribution of microorganisms

It has been hypothesized that plankton patchiness exists on scales of tens to hundreds of micrometers (nanoscale patchiness). Current sampling methods disrupt the spatial pattern on this scale and therefore cannot detect nanoscale patchiness. We describe a method that allows the collection of microorganisms and other particles without destroying their relative spatial distribution. Our spatial information preservation (SIP) method is based on rapidly freezing a small sample of water. The three-dimensional particle distribution captured in the ice is preserved in two dimensions as a projection on a microscope slide. Experiments were conducted on the extent of particle movement during freezing and removal of ice from around the particles, as well as the potential for cell loss during these procedures. The experiments demonstrate that microorganisms can be collected quantitatively with sufficient preservation of their spatial distribution to resolve nanoscale patchiness.