Figure 1. A schematic description of the whole transformation process from cryosections to matched layers representation and statistical evaluation.

(A) The two cryosections were sliced from tissue, (B) the narrow slice is used for histological analysis and to find uniform spots - red - GMT (normally growing melanoma tissue), violet - ESR (early spontaneous regression), yellow - LSR (late spontaneous regression) and green - FT (fibrous tissue). (C) The wide slice is photographed and (D) measured by LA-ICP-MS. (E) The measured elemental maps are normalized with respect to dry weight. The slices are registered in two steps. (F) Firstly, the normalized metal maps are registered with the slice photography and secondary, the result of the first step is registered with the histological scan. The registration is based on silhouette registration. (G) The output of the process is a layered representation of tissue consisting of a histological layer with selected spots and metal layers. (H) The layered representation of all tissues is statistically evaluated. Our data confirm the hypothesis that content of zinc in the zone of growing melanoma tissue (GMT) is significantly greater than in all remaining zones.