Basement membranes are continuous sheets of the specialized extracellular matrix that form an interface between endothelial, epithelial, muscle, or neuronal cells and their adjacent stroma. Basement membranes are degraded and regenerated during development and wound healing. They not only support cells and cell layers, but they also play an essential role in tissue organization that affects cell adhesion, migration, proliferation, and differentiation. Basement membranes provide major barriers to invasion by metastatic tumor cells.
Cultrex® Basement Membrane Extract (BME) is a soluble form of basement membrane purified from Engelbreth-Holm-Swarm (EHS) tumor. The extract gels at 37 ⁰C to form a reconstituted basement membrane. The major components of BME include laminin, collagen IV, entactin, and heparin sulfate proteoglycan.
BME can be used in multiple applications, under a variety of cell culture conditions, for maintaining growth or promoting differentiation of primary endothelial, epithelial, smooth muscle, and stem cells. BME can also be utilized in cell attachment, neurite outgrowth, angiogenesis, in vitro cell invasion, and in vivo tumorigenicity assays. Recently we have developed two additional formulations of Cultrex® BME known as Cultrex® BME Type 2 and Cultrex® BME Type 3. Cultrex® BME Type 2 provides a proprietary formulation that is higher in tensile strength when compared to our original BME, while Cultrex® BME Type 3 is physiologically aligned with the in vivo solid tumors environment and is recommended for xenografts and other in vivo applications.
The product is stable for a minimum of 3 months from date of shipment when stored at –20 ⁰C in a manual defrost the freezer. For optimal stability, store at –80 ⁰C. Avoid freeze-thaw cycles.
Thaw Cultrex® BME overnight at 2-8 ⁰C. Refrigerator temperatures may vary; therefore it is recommended to keep BME on ice in a refrigerator during the thawing process. Thawed BME solidifies quickly at the temperatures above 15 ⁰C; when working with extract, keep it on ice to prevent untimely gelling.
There are many applications for Cultrex® BME, which require different thicknesses and concentrations. In general, BME at a protein concentration ≥ 10 mg/mL is used for differentiation studies of primary cells. For applications such as endothelial cell formation of capillary-like structures (Tube Formation Assay), the differentiation of rat aorta tissue into capillary-like structures (Aortic Ring Assay), epithelial organoid formation, or tumor organoid formation, a thick gel is needed. Some applications, such as propagation of primary cells, require a thin layer coating and not a thick gel; therefore, the thin layer method should be used.
Thick Gel Method
Thin Layer Method (non-gelling)
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