Fibroblasts are mesenchymal cells derived from the embryonic mesoderm. They have been extensively used for a wide range of cellular and molecular studies as they are one of easiest types of cells to grow in culture. Their durability also makes them amenable to a variety of manipulations ranging from studies employing gene transfection to microinjection. In general, fibroblasts secrete a non-rigid extracellular matrix which is rich in type I and/or type III collagen. There is evidence showing that fibroblasts in various organs are intrinsically different. In the lymphoid compartment, fibroblasts construct a unique conduit system with intriguing size exclusion which plays a fundamental role in regulating immune response and homeostasis of tissue fluids. MLF from ScienCell Research Laboratories are isolated from C57BL/6 mouse lymph node. MLF are cryopreserved at P0 and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. MLF are characterized by their spindle-shaped morphology and immunofluorescence with antibody specific to fibronectin. MLF are negative for mycoplasma, bacteria, yeast, and fungi. MLF are guaranteed to further expand for 5 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Fibroblast Medium (FM, Cat. #2301) for culturing MLF in vitro.