Fluorescence microscopy tissue selection

Biggs A R 1985 Detection of impervious tissue in tree bark with selective histochemistry and fluorescence microscopy. Stain Tech 60 299-304... 

As previously discussed, electron, light, and confocal microscopy techniques may be used to visualize the position of electron-dense precipitates, radioactive substances, and fluorescent probes, respectively, in the sample tissue. However, none of these techniques possess the capability both to visualize and to selectively measure the flux of a molecule across the skin. SECM, however, permits the measurement and subsequent imaging of the local flux of an electroactive species across biological membranes. Scott et al. [3] used SECM to investigate the effect of pretreatment of the penetration enhancer sodium dodecyl sulfate (SDS), on the ion transport rate and transport pathways of Fe(CN) across hairless mouse skin. Increasing the time of SDS exposure from 10 min to 30 min increased the overall (porous and nonporous) transport of Fe(CN) by 17-fold. More specifically, the SDS-induced increase in Fe(CN)g transport was found to be associated with nonporous (i.e., intercellular) transport routes, while transport via porous routes was significantly reduced. The fraction of Fe(CN)g transport through pores, as measured by... 

Figure 2. (a) HE histology demonstrates a tumor island within normal brain tissue, (b) Confocal laser scanning microscopy of a GBM after sensitisation with mTHPC fluorescence localised within the tumor cells, indicating selective uptake of the sensitiser. (c) Giant tumor cell imbedded in normal brain tissue, demonstrating selective uptake into tumor cells. 

Confocal scanning laser microscopy has been combined with the use of fluorescent stains to measure the distribution and concentration of specific analytes within biological tissue. Stains are used to bind selectively with the analyte under study, and the correct laser beam is selected to excite the stain used to give a fluorescent signal. The technique can also be... 

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