The 2nd generation Environmental Sample Processor: Evolution of a robotic underwater biochemical laboratory

Many of the diagnostic protocols for detecting molecular signatures share an overlapping set of requirements, such as collecting, concentrating, preserving and disrupting cells, applying a series of reagents in a timed sequence, removing particulates, and applying solid phase extraction chemistries, among others. Operationally, these methods can be divided into those that depend on intermolecular reactions, such as antibody/antigen binding, nucleic acid hybridization and enzyme mediated processes, and those that rely on separation and identification of target molecules based on their inherent physical properties. Optical and electrochemical transducers are used commonly to detect and quantify numerous molecular signatures. By developing a relatively low-power, compact instrument that meets this core set of functional requirements, it would be possible to conduct many commonly applied molecular biological analyses remotely, in situ. Toward that goal, a group of scientists and engineers at the Monterey Bay Aquarium research Institute (MBARI) undertook development of the Environmental Sample Processor. The ESP is an electromechanical/fluidic instrument system designed to collect discrete water samples from the ocean subsurface, concentrate microorganisms (particulates), and automate application of molecular probes to identify microorganisms based on ribosomal RNA (rRNA) signature sequences. In addition, the ESP archives discrete samples for a variety of nucleic acid analyses, microscopy and other types of analytical procedures after the instrument is recovered. To date, the ESP team has focused on detecting a suite of marine planktonic organisms ranging from heterotrophic and photosynthetic bacteria, archaea and eucarya to small invertebrates found in the upper ocean. "First generation" (or "1G") prototypes of the ESP have been deployed in Monterey Bay and the Gulf of Maine