In-Situ mRNA Sample Homogenizer (iSMASH)
The in Situ MAcerator and Sample Homogenizer (iSMASH) is an open access tool that allows us to preserve gene and protein expression in situ. (Peter Girguis)
The iSMASH in situ preservation system was used to collect and preserve carbonate samples from the Southern California seafloor. (Peter Girguis / Schmidt Ocean Institute)
The iSMASH in situ preservation system was used to collect and preserve carbonate samples from the Southern California seafloor. (Peter Girguis / Schmidt Ocean Institute)
To date, studying gene expression has been practically impossible to do at depth, as the organisms alter their transcriptomic RNA expression quickly during recovery to the surface. For very small organisms, such as microbes or meiofauna, there are some remarkable tools that enable one to study gene expression in situ. With larger invertebrates or other animals, however, the relative rate of preservative diffusion through tissues is much slower. In these organisms, dropping them into preservative will likely cause dramatic shifts in expression before transcription is halted, resulting in artifacts in transcription.
To enable effective analyses of gene expression in freshly collected organisms, we developed the in-Situ mRNA Sample Homogenizer (or iSMASH) that macerates and preserves organisms in RNA fixative in situ. iSMASH is a set of hydraulically-powered custom blenders that quickly homogenize samples in an RNA preservative solution at the seafloor. The entire process takes very little time, circa three to five minutes, yielding high-quality transcriptomic data that are likely to be much more representative of the conditions experienced by the organisms in nature. This approach has proven to be an excellent means of examining physiological “poise” in deep-sea animals.
All parts and drawings are available upon request.
