Inclusion Criteria:  Adults scheduled to undergo Mohs surgery within the Dermatologic Surgery unit of the Department of Dermatology, Cleveland Clinic Must have at least two BCC tumors eligible for removal by Mohs surgery Men and women of any ethnic group are eligible Must provide informed consent to participate  Exclusion Criteria:  Pregnant or breastfeeding Currently being treated for other cancers with medical or radiation therapy Known hypersensitivity to 5-aminolevulinic acid (ALA) History of a photosensitivity disease, e.g.,porphyria cutanea tarda