SummaryUsing a 2:1 chloroform methanol solution and Versatm detergent diluted with deionized water we cleaned feather samples of oil\/debris for stable isotope analysis of carbon (\u03b413C), nitrogen (\u03b415N), and hydrogen (\u03b42H). Prepared samples were then measured, cut, and packaged in tin or silver capsules for analysis of carbon(\u03b413C) and nitrogen(\u03b415N) or hydrogen(\u03b42H), respectively. We aim to standardize the laboratory procedure across institutions and research groups focused on avian ecology and conservation and to improve result accuracy and reproducibility.Background Stable isotope analysis of relatively abundant elements such as carbon (\u03b413C), nitrogen (\u03b415N), and hydrogen (\u03b42H) have been widely implemented, particularly over the past two decades, in ecology, conservation, and forensic studies (Vander Zanden et al. 2018.). For example, stable isotope analyses of biological tissues can reveal useful information on diet, trophic level interactions, and large scale animal movements (Bridge et al. 2011; Contina et al. 2013; Zenzal et al. 2018). However, laboratory sample preparation for stable isotope studies requires a standardized protocol to ensure accuracy and repeatability of the results (Paritte and Kelly 2009).Corresponding author: firstname.lastname@example.org Useful references:Zenzal T.J. et al. 2018. Temporal migration patterns between natal locations of ruby-throated hummingbirds (Archilochus colubris) and their Gulf Coast stopover site. Movement ecology, 6(1), p.2.Vander Zanden et al. 2018. Application of isoscapes to determine geographic origin of terrestrial wildlife for conservation and management. Biological conservation, 228, pp.268-280.Contina et al. 2013. Using geologgers to investigate bimodal isotope patterns in Painted Buntings (Passerina ciris). The Auk, 130(2), pp.265-272.Bridge et al. 2011. Causes of bimodal stable isotope signatures in the feathers of a molt-migrant songbird. Canadian Journal of Zoology, 89(10), pp.951-959.Paritte and Kelly 2009. Effect of cleaning regime on stable-isotope ratios of feathers in Japanese Quail (Coturnix japonica). The Auk, 126(1), pp.165-174.