I owe a great deal of gratitude to Sami for this trip and all the work she has done with Jim McGrath to pull the MP community together, give me ideas for my own research, and forging connections around the country.
Sami emailed me in 2021 when she and Jim launched the Rochester Microplastics Working Group, now expanded to be the Western NY Microplastics Working Group, with nearly 50 members from 9 different institutions who get together (virtually of course) once a month to talk microplastics. One wouldn’t expect to find someone who had completed her PhD in Cellular and Molecular Pharmacology and Physiology from University of Nevada to be preparing bat guts and tadpoles for microplastic analysis in Rochester, NY, but there is little ordinary about Sami. She is extraordinary. In addition to bats and tadpoles, Sami and Garrett Cashion, a senior undergraduate student studying environmental health and medicine, had samples on deck for analysis (see above). These include household dust, some of my drinking water samples, and atmospheric dust samples from Black Rock Desert, where a temporary city is constructed to host the Burning Man event. Sami sees this as a unique opportunity to study the impact of urbanization on microplastic deposition. Unfortunately, neither the tire wear particles nor the charcoal in these samples will take up the dyes, so she’ll have to use heat and/or Raman spectroscopy to tell them apart. Stay tuned.
Working with the geniuses at SiMPore, a Rochester-based nanotech firm, this team has perfected using a small chip with membrane windows in a modified centrifuge tube (SepConTM). Sami dyes her samples with Nile Red and trypan blue and spins them in a mini-centrifuge to force all the little microplastics into the membrane pores, and then looks for microplastics systematically with a Nikon epifluorescent microscope.
Below is an image of a household dust sample we looked at. The dust was suspended in ultrapure water before filtered through an 8-micron SiMPore Inc. microslit membrane. It shows Nile red stained plastics (nylon, PET, etc.), trypan blue stained cellulosic materials (cotton/hemp/linen, dead skin cells, insect parts, etc), and unstained particles (black) are of proteinaceous (wool/silk/hair/fur) or inorganic nature (metals, etc). Unfortunately, neither the tire wear particles nor the charcoal in these household dust and Black Rock Desert samples will take up Nile Red dye, so she’ll have to use Raman spectroscopy to tell them apart. Stay tuned.
Being in the same building as the Department of Optics has its benefits; the Raman instrument is custom-made by a series of mirrors and concentrators perfectly positioned on a table- there is no make and model!
Sami and I talked about how much plastic we use to analyze for microplastics: the Ziploc bags for sample storage, the centrifuge tubes, the pipette tips, the packaging of the supplies we order. Sometimes it feels like a losing game, but hopefully just in the short-term. We also talked about how Sami would set up a microplastics research lab if she was starting from scratch: there would be lockers or cubbies for personal items far away from the benches, floor mats to catch particles from shoes, bench hoods and HEPA filters. Wouldn’t that be nice! Hopefully, that day is coming soon for this rock star of science!