Lonza’s Normal Human Articular Chondrocytes (NHAC-kn) are differentiated cells which express collagen when they are initially isolated, however, they lose their differentiated phenotype after serial expansion in monolayer culture so that by the 2nd or 3rd passage from cryopreservation, the culture is almost 100% de-differentiated and no longer express collagen.
The cells can be expanded in culture, then induced to re-differentiate to once again express collagen. In culture, chondrocytes de-differentiate and exhibit heterogeneous morphologies, from fibroblastic to polygonal.