Lonza guarantees that the Normal Human Articular Chondrocytes (NHAC-kn) will express collagen Type II and sulfated proteoglycans (can be stained with Alcian Blue) upon re-differentiation. Lonza’s recommended differentiation protocol does induce hypertrophic (terminal) differentiation and Lonza does not test for collagen Type X, produced exclusively by hypertrophic chondrocytes.