Chondrocytes are the resident cells of cartilage and are responsible for synthesizing a range of collagenous and non-collagenous extracellular matrix macromolecules. These include collagen type II, aggrecan, link protein, collagen type IX, and collagen type XI. The control of proliferation and differentiation of chondrogenic cells is central to the coordinated development of the vertebrate skeleton. Chondrocytes are capable of producing and responding to a large number of peptide growth factors and cytokines, including insulin-like growth factor-1 and interleukin-1. Chondrocyte cultures are useful in vitro models for studying cartilage regeneration and repair, cytokine and growth factor effects on cartilage, specific gene regulation and pathophysiology of arthritis. HC-a from ScienCell Research Laboratories are isolated from human articular cartilage. HC-a are cryopreserved at passage one and delivered frozen. Each vial contains >5 x 105 cells in 1 ml volume. HC-a are characterized by immunofluorescence with antibodies specific to S100B and/or type II collagen. HC-a are negative for HIV-1, HBV, HCV, mycoplasma, bacteria, yeast and fungi. HC-a are guaranteed to further expand for 15 population doublings under the conditions provided by ScienCell Research Laboratories. Recommended Medium It is recommended to use Chondrocyte Medium (CM, Cat. #4651) for the culturing of HC-a in vitro.