Organoid cultures are extracted directly from living tissues similar to primary cultures. When subjected to differentiating conditions, these organoids exhibit expression of tissue-specific genes and differentiation of stem cells into tissue-specific architecture and cell types. Cultrex® Organoid Progenitor Cells from Mouse Small Intestine are derived from normal, healthy mouse small intestine tissue and are continuously cultured using Reduced Growth Factor BME-R1 and BME 2. They are never cultured directly on tissue-culture treated plastic surfaces. These organoid progenitor cells can be expanded on BME and may be induced to express tissue specific markers under differentiating conditions.