A method for analyzing tissue and controlling depth of imaging of the tissue, comprising: obtaining a tissue sample; exposing the tissue sample to one or more fluorophores including fluorescent dyes or fluorescently labeled molecular probes that preferentially accumulate in tissue or cellular components and that can be sufficiently excited in a first spectral range, the first spectral range being from 350 nm to 200 nm, and that have useful emission bands in a second, different spectral range, the second spectral range being from 350 nm to 950 nm; using an illumination excitation source to illuminate a surface of the tissue sample with an ultraviolet, "UV", light source; using a microscope optical system to image the tissue sample; using an image acquisition system which receives optical information from the microscope optical system to record one or more images occurring in the second spectral range of 350 nm to 950 nm; and using a display system in communication with the image acquisition system to process and display the image for analysis, wherein the illumination of the tissue sample with UV light comprises using a UV light source having a wavelength band with a center wavelength selected from: 290 nm; 280 nm; 270 nm; 260 nm; 250 nm; 245 nm; 240 nm; 235 nm; 230 nm; 225 nm; 220 nm; 210 nm; 200 nm; and wherein the UV light source comprises at least one of: a LED; a laser; a tunable laser; or a continuous source including at least one of a continuum laser light source, an arc-lamp, a laser-ignited arc lamp, a krypton-bromine excimer lamp, or other sources with sufficient brightness in the desired spectral range; characterized in that a depth of penetration of the UV light in the tissue sample is controlled by controlling both: a specific wavelength selected for the UV light which limits a penetration depth of the UV light into the tissue sample to only an approximate selected depth below a surface of the tissue sample; and a selected incidence angle of for the UV light relative to a surface of the tissue sample, where the selected incidence angle of the UV light is an oblique incidence angle moving towards 90 degrees or an incidence angle of 90 degrees relative to the surface of the tissue sample. obtaining a tissue sample; exposing the tissue sample to one or more fluorophores including fluorescent dyes or fluorescently labeled molecular probes that preferentially accumulate in tissue or cellular components and that can be sufficiently excited in a first spectral range, the first spectral range being from 350 nm to 200 nm, and that have useful emission bands in a second, different spectral range, the second spectral range being from 350 nm to 950 nm; using an illumination excitation source to illuminate a surface of the tissue sample with an ultraviolet, "UV", light source; using a microscope optical system to image the tissue sample; using an image acquisition system which receives optical information from the microscope optical system to record one or more images occurring in the second spectral range of 350 nm to 950 nm; and using a display system in communication with the image acquisition system to process and display the image for analysis, wherein the illumination of the tissue sample with UV light comprises using a UV light source having a wavelength band with a center wavelength selected from: 290 nm; 280 nm; 270 nm; 260 nm; 250 nm; 245 nm; 240 nm; 235 nm; 230 nm; 225 nm; 220 nm; 210 nm; 200 nm; and 290 nm; 280 nm; 270 nm; 260 nm; 250 nm; 245 nm; 240 nm; 235 nm; 230 nm; 225 nm; 220 nm; 210 nm; 200 nm; and wherein the UV light source comprises at least one of: a LED; a laser; a tunable laser; or a continuous source including at least one of a continuum laser light source, an arc-lamp, a laser-ignited arc lamp, a krypton-bromine excimer lamp, or other sources with sufficient brightness in the desired spectral range; a LED; a laser; a tunable laser; or a continuous source including at least one of a continuum laser light source, an arc-lamp, a laser-ignited arc lamp, a krypton-bromine excimer lamp, or other sources with sufficient brightness in the desired spectral range; characterized in that a depth of penetration of the UV light in the tissue sample is controlled by controlling both: a specific wavelength selected for the UV light which limits a penetration depth of the UV light into the tissue sample to only an approximate selected depth below a surface of the tissue sample; and a selected incidence angle of for the UV light relative to a surface of the tissue sample, where the selected incidence angle of the UV light is an oblique incidence angle moving towards 90 degrees or an incidence angle of 90 degrees relative to the surface of the tissue sample. a specific wavelength selected for the UV light which limits a penetration depth of the UV light into the tissue sample to only an approximate selected depth below a surface of the tissue sample; and a selected incidence angle of for the UV light relative to a surface of the tissue sample, where the selected incidence angle of the UV light is an oblique incidence angle moving towards 90 degrees or an incidence angle of 90 degrees relative to the surface of the tissue sample.