Public Microbial Resource Centers: Key Hubs for Findable, Accessible, Interoperable, and Reusable (FAIR) Microorganisms and Genetic Materials.

In the context of open science, the availability of research materials is essential for knowledge accumulation and to maximize the impact of scientific research. In microbiology, microbial domain biological resource centers (mBRCs) have long-standing experience in preserving and distributing authenticated microbial strains and genetic materials (e.g., recombinant plasmids and DNA libraries) to support new discoveries and follow-on studies. These culture collections play a central role in the conservation of microbial biodiversity and have expertise in cultivation, characterization, and taxonomy of microorganisms. Information associated with preserved biological resources is recorded in databases and is accessible through online catalogues. Legal expertise developed by mBRCs guarantees end users the traceability and legality of the acquired material, notably with respect to the Nagoya Protocol. However, awareness of the advantages of depositing biological materials in professional repositories remains low, and the necessity of securing strains and genetic resources for future research must be emphasized. This review describes the unique position of mBRCs in microbiology and molecular biology through their history, evolving roles, expertise, services, challenges, and international collaborations. It also calls for an increased deposit of strains and genetic resources, a responsibility shared by scientists, funding agencies, and publishers. Journal policies requesting a deposit during submission of a manuscript represent one of the measures to make more biological materials available to the broader community, hence fully releasing their potential and improving openness and reproducibility in scientific research.

An easy and versatile embedding method for transverse sections.

In several research areas, transverse sections are indispensable for studying structural aspects of specimens. However, the oriented embedding of small cylindrical samples can become problematic, especially when transverse sections at right angles to the main axis of the object are desired. Here, we describe an easy and low-cost technique for oriented embedding of small (psi < 500 micro m) as well as of larger specimens (psi > 500 micro m). The usefulness of the technique is demonstrated for roots and stamens of Arabidopsis thaliana and for adventitious roots of Asplenium demerkense, as examples of small and larger cylindrical samples, respectively. Furthermore, several types of resin (glycol methacrylate, epoxy and acrylic resins) were successfully tested, showing the applicability of the technique for light and electron microscopy and for immunolocalizations. In conclusion, the principle of the technique can be extended to several resins and a wide variety of specimen types, such as stems, leaves and textile fibres. The originality of the technique lies in its simplicity combined with its high efficiency to produce well-oriented transverse sections.