This study investigates the presence of RNA in exosomes from human saliva, plasma, and breast milk, and examines whether these exosomes can be taken up by macrophages. Exosomes were purified from these body fluids using ultracentrifugation and filtration, and their presence was confirmed by electron microscopy and flow cytometry. RNA was detected in all three types of exosomes, with a portion of the RNA in plasma exosomes identified as mRNA. Western blot analysis confirmed the presence of Hsc70 and CD81 in breast milk exosomes but not calnexin, indicating their exosomal origin. The uptake of PKH67-labeled saliva and breast milk exosomes by macrophages was observed using flow cytometry and fluorescence microscopy. The findings suggest that exosomes from human saliva, plasma, and breast milk contain RNA and can be taken up by human macrophages, potentially facilitating RNA transfer between cells. This study highlights the potential role of exosomes in genetic communication and immune regulation in various biological contexts.This study investigates the presence of RNA in exosomes from human saliva, plasma, and breast milk, and examines whether these exosomes can be taken up by macrophages. Exosomes were purified from these body fluids using ultracentrifugation and filtration, and their presence was confirmed by electron microscopy and flow cytometry. RNA was detected in all three types of exosomes, with a portion of the RNA in plasma exosomes identified as mRNA. Western blot analysis confirmed the presence of Hsc70 and CD81 in breast milk exosomes but not calnexin, indicating their exosomal origin. The uptake of PKH67-labeled saliva and breast milk exosomes by macrophages was observed using flow cytometry and fluorescence microscopy. The findings suggest that exosomes from human saliva, plasma, and breast milk contain RNA and can be taken up by human macrophages, potentially facilitating RNA transfer between cells. This study highlights the potential role of exosomes in genetic communication and immune regulation in various biological contexts.