Researchers Sam Urlacher and Josh Snodgrass had a problem. The pair had been working together since 2011 to better understand how immune activity hinders children’s growth under a range of preindustrial and urban living conditions. Urlacher, then a graduate student at Harvard University, and Snodgrass, a biological anthropologist at the University of Oregon, needed a reliable way to measure children’s immune responses to infection by pathogens and parasites.
But commercially available kits to test for biomarkers of immune system activity required vials of serum or plasma—a no-go when working with their planned study cohort, children living in indigenous communities deep in the Amazon. It would have been impossible to store the biofluids properly until they could be analyzed, and neither the scientists nor the children and their parents would have wanted to carry out multiple blood draws over weeks or months. So Urlacher, Snodgrass, and colleagues had to devise their ...
