IPATIMUP 1 article published in JoVE Developmental Biology A Standardized Approach for Multispecies Purification of Mammalian Male Germ Cells by Mechanical Tissue Dissociation and Flow Cytometry Ana C. Lima*1,2,3,4, Min Jung*1, Jannette Rusch1, Abul Usmani1, Alexandra M. Lopes3,4, Donald F. Conrad1 1Department of Genetics, Washington University School of Medicine, 2Graduate Program in Areas of Basic and Applied Biology (GABBA), Abel Salazar Institute of Biomedical Sciences, University of Porto, 3Instituto de Investigação e Inovação em Saúde, University of Porto, 4IPATIMUP - Instituto de Patologia e Imunologia Molecular da Universidade do Porto, 5Department of Pathology & Immunology, Washington University School of Medicine This work describes the standardization of a method to obtain purified germ cell populations from testicular tissue of different mammalian species. It is a straightforward protocol that combines mechanical testis dissociation, staining with Hoechst-33342 and propidium iodide, and FACS sorting, with wide applications in comparative studies of male reproductive biology.