This invention provides a cost-effective method for isolating high-purity exosomes from various sample types, including plant extracts from which exosomes could not previously be obtained. The method uses a two-phase fluid extraction system with dextran and PEG to separate proteins and unwanted substances. Subsequent washing and dextran removal steps allow collection of exosomes in a pure form. This technology establishes a new standard for exosome-based therapies and diagnostic applications in biotechnology and medical fields.