Abstract Microplastics (MPs) are a ubiquitous pollutant in natural waters and in foods and drinks derived from them. Not surprisingly, MPs are ingested and inhaled by humans and found in human tissues. Research on MPs is made difficult by the labor intensive protocols associated with isolating MPs from environmental and biological tissues, particularly at the size scales most relevant to human health (< 20 µm). Researchers also need access to trusted reference MPs that mimic those found in the environment. This Materials and Metrology Core (MMC) will serve as a resource that addresses these bottlenecks to increase the efficiency and reproducibility of research in Center laboratories. The specific functions of the MMC are organized into three Aims. Aim 1 will provide key research materials to the Center. These include laboratory-made mimetics of environmental MPs for use as reference and control materials. As one novel resource, the MMC will work with Project 1 to adopt protocols generating MPs reflecting the types and aging of MPs found in Lake Ontairo. Another unique resource of the MMC will be an inventory of silicon nanomembranes with various pore sizes. These inorganic membranes feature precision patterned pores in size ranges < 20 µm and high permeability. The properties of silicon nanomembranes enable the development of novel time-saving protocols for MP isolation, detection, and analysis. In these methods, raw samples are added to nanomembranes housed in filtration devices and serially processed in situ until they are ready for imaging or spectroscopic analysis. The elimination of manual transfers saves time while minimizing the risk of loss and contamination. In Aim 2 the MMC will work with member laboratories to develop consensus protocols that are demonstrably reproducible and rigorous and will share these through web resources. In Aim 3 the MMC will facilitate access to the growing number of high-end tools and facilities in the Rochester area for MP research such as Raman instruments, electron microscopes, and cyromilling instruments. The MMC will also play a role in the public distrubtion of the products emerging from the Center, including consensus protocols, through the creation of a dedicated microplastics subsection of nanomembranes.org.