M-INK, a novel tool for visualizing melanosomes and melanocores.

Melanosome transfer from melanocytes to surrounding keratinocytes is one of the crucial but less well-characterized steps in the process of skin pigmentation. Although several markers have generally been used to detect melanosomes in melanocytes, no suitable markers for melanosomes that have been transferred into keratinocytes have ever been reported. The melanocore-interacting Kif1c-tail (M-INK) probe we developed and reported here specifically recognizes melanocores and thus makes visualizing melanosomes that have been incorporated into keratinocytes possible even in a fluorescent field. M-INK staining makes it possible to reconstruct 3D images of melanosome-containing keratinocytes, and thereby precisely localize melanosomes in keratinocytes.