Our approach for assessing chemistry and functional in biological models. The protocols discussed in this chapter were developed and validated using embryos from the frog Xenopus laevis and zebrafish and sections from the mouse brain. (Adapted with permission from Anal. Chem. 2017, 89, 13, 7069–7076. Copyright 2017 American Chemical Society. Adapted with permission from Anal. Chem. 2019, 91, 7, 4797–4805. Copyright 2019 American Chemical Society.)