Ultrastructural localization of HMB‐45 binding sites

Abstract
Three malignant melanomas, two melanoma metastases, two junctional dysplastic nevi, and normal skin were embedded in Lowicryl. Ultrathin sections were incubated with HMB-45 and a gold-labeled anti-mouse antibody. Gold particles indicating the presence of HMB-45 were found in melanosomes Stage 1 and 2 and in the non-melanized portion of melanosomes Stage 3. Melanosomes Stage 4 and melanosome complexes in keratinocytes, as well as in melanophages, were consistently negative. No specific labelling with HMB-45 was seen in eccrine glands of normal skin.
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