Early diagnosis of melanoma is critical for improved survival as melanoma is the deadliest of the common forms of skin cancer. The gold standard for the diagnosis of melanoma is a biopsy followed by histopathological analysis. Melanocytic nevi, which are very common benign neoplasms of the melanocytes, are often biopsied because they are mimics and precursor for melanoma. Annually, 4.5 million pigmented lesions are biopsied in the United States. A subset of melanoma is difficult to distinguish from melanocytic nevi, resulting in diagnostic errors and worsened patient outcomes. Therefore, improved diagnostic tests, including the utilization of novel biomarkers, are being developed to improve clinical and histological diagnostic accuracy of melanoma. Moreover, non-invasive tests prior to surgical biopsy have been introduced, including an adhesive patch-based assay that tests the expression of melanoma biomarkers PRAME and noncoding long RNA LINC00518. Our prior work identified that S100A8, a member of the calcium-binding S100 family, is differentially expressed in melanomas versus nevi4 . Specifically, S100A8 is expressed by the keratinocyte microenvironment of melanomas but not nevi. S100A8 is a melanoma biomarker of interest for an adhesive patch-based assay, because it is expressed in the epidermis, the most superficial layer of the skin.