Fluorescently labeled mAb signals in fetal and maternal tissues measured by whole-body hyperspectral imaging. To assess maternally administered Ab biodistribution, conjugated Ab was administered IV on day 15 or 16 of gestation, then 2–3 d later tissues were prepared for imaging with the whole body cryo-macrotome, mAb admin (dam n = 1, pup n = 4), mAb admin. + dissection (dam n = 1, pup n = 6). Control background fluorescence was determined in a pregnant dam not injected with conjugated Ab (dam n = 1, pup n = 4). Each dot represents the average intensity value of all voxels for a single animal, bar represents the full cohort’s geometric mean fluorescence intensity value, and the error is reported as geometric standard deviation (n = 4–6 per cohort).