Virginia Surgery Associates 1 article published in JoVE Biology Non-enzymatic, Serum-free Tissue Culture of Pre-invasive Breast Lesions for Spontaneous Generation of Mammospheres Virginia Espina1, Kirsten H. Edmiston2, Lance A. Liotta1 1Center for Applied Proteomics and Molecular Medicine, George Mason University, 2Virginia Surgery Associates Primary cell culture using intact tissue organoids provides a model system that mimics the multi-cellular in vivo microenvironment. We developed a serum-free primary breast epithelium tissue culture model that perpetuates mixed cell culture lineages and exhibits differentiated morphology, without enzymatic tissue disruption. Breast organoids remain viable for >6 months.