A method for determining the degree of sensitivity of a strain of fungus to an antifungal agent by using the possible change in a chitin level in a population of cells of a strain of fungus to an antifungal agent. The change is determined compared to the chitin level of a population of cells of said strain of fungus in the absence of antifungal agent.

A method of detecting a covert marking including applying a fluorescent ink to a dendritic structure to generate an ink-coated dendrite and imaging the ink-coated dendrite with a device to visualize the ink-coated dendrite. A method of detecting a covert marking on an object including applying UV light to an object including a dendritic structure and illuminating the dendritic structure with the UV light. A dendritic structure including a unique metallic structure at least partially coated with a fluorescent ink that is not visible to the naked eye in ambient light and is visible to the naked eye when exposed to UV light.

An apparatus (100) for optically characterizing a textile sample (106) comprises a presentation subsystem (102) comprising a viewing window (108). A radiation subsystem (114) comprises a radiation source (120) for directing a first, ultraviolet radiation (122) and a second, visible radiation (123) toward the sample (106), and causing the sample (106) to produce a fluorescent radiation (124) and a reflected radiation (125). A sensing subsystem (126) comprises an imager (130) for capturing the fluorescent radiation (124) and the reflected radiation (125) in an array of pixels (408). A control subsystem (132) comprises a processor (136) for controlling the presentation subsystem (102), the radiation subsystem (114), and the sensing subsystem (126), and for creating a fluorescent and reflected radiation image (400) containing both spectral information and spatial information in regard to the fluorescent radiation (124) and the reflected radiation (125).