Periphyton growing and sampling in situ or in mesocosm for metabolomic analysis v2

This document describes the various steps involved in recovering biofilm exposed in mesocosm (on glass slides) or in the natural environment (on glass slides or natural substrates) for metabolite analysis. The aim is to describe the procedures as exhaustively as possible so that all samples are treated in the same way. The sample fixation (quenching) step is a key step that must be performed as quickly as possible to ensure the accuracy of the results. Depending on the feasibility of quenching in the fieldor in the laboratory, a choice must be made between liquid nitrogen and dry ice.