The kINPen®MED plasma device, which is approved for the treatment of chronic wounds, was investigated in vitro with regard to a possible effect on skin pigmentation. To this end, investigations were first carried out on melanoma cells. Melanoma cell lines with different levels of pigmentation were exposed to an indirect plasma treatment, that is, incubated with plasma-treated cell culture medium, and the melanin content was evaluated before and after the treatment by means of a UV spectroscopic analysis. Compared to the untreated cells, the melanin content of all tested melanoma cell lines was increased. Also in comparison to cells that were treated with the positive controls IBMX or NH4Cl / tyrosine, an increased effect of the plasma treatment on the pigmentation of the melanoma cells was shown. Since melanoma cells are not primarily the target of therapeutically indicated effects on pigmentation, the next step was to determine the melanin content of primary melanocytes after in vitro plasma treatment. To this end, the method for relative melanin quantification was fundamentally revised. Two different methods for improved melanin analysis have been developed, which have a higher sensitivity with regard to the required amount of sample compared to the UV spectroscopic determination of the melanin content in the melanoma cell model. As described in the literature, the first method is based on the oxidation of melanin in an alkaline solution using hydrogen peroxide and ...