How can I be sure that the cells in my melanocyte culture are melanocytes? Have I understood it correctly that the medium is selective for melanocytes?

After isolation and purification of our primary human melanocytes, the cells are checked during quality control whether they show a typical morphology and whether they express the marker Mel-5. Mel-5 is a 75 kDa glycoprotein usually expressed by normal melanocytes. Our Melanocyte Growth Medium (C-24010) has been developed to promote melanocyte growth in vitro. It does not however, completely block the growth of other cells (such as: NHEK or NHDF). 

Therefore, it is important to have a pure melanocyte culture from the very beginning. 

In contrast, the Melanocyte Growth Medium M3 (C-24310) is much more selective and represses the growth of contaminating cells much better.