presents the photos of the soft gold ultramicroelectrode gently scanned on the human oral cancer tissue biopsy array and the tissue section on the glasses in contact mode without damaging fragile samples. Compared with conventional assays, such as fluorescent staining or immunohistochemistry (IHC), SECM can avoid optical interferences, including skin pigmentation and autofluorescence, to assist the clinical study of samples with a darker color or can be used along with other optical methods.