A restaining method to restore faded fluorescence in tissue specimens for quantitative confocal microscopy.

The aim of this study was to develop a procedure to remove the TO-PRO-3 fluorescent dye from tissue sections and restain with TO-PRO-3, still allowing calculation of DNA content and distribution by confocal laser scanning microscopy (CLSM). This would allow repeated measurements on the same tissue sections and prevents loss of tissue material from valuable clinical samples. Thick sections (14 microm) were cut from a paraffin block of adrenal tissue and stained using TO-PRO-3.